O-Word Vocabulary Definitions

oakum. hemp or jute fiber with tar, creosote, or asphalt, for caulking ships, pipes
oak will. oak tree disease
oarfish. 30 feet long
oast. kiln: hops, malt, tobacco
obligato. not to be left out
obcordate. heart-shaped, attached at bottom of heart
obesh. West Indies voodoo
obelia. marine hydroids
obelus. mark (— or )used in ancient manuscripts to show doubtful or spurious
obi. wide sash worn by Japanese women
Obie. Off-Broadway award
obiter dictum. side remark (opinion voiced by judge that has only incidental bearing)
objective complement. "They elected him governor") Noun complements the verb
objective correlative. situation that objectifies an emotion to elicit a response from reader
objectivism. reality is real; objective themes in art
objet trouvé. a found object
objurgate. to sharply rebuke, berate
oblanceolate. broader and rounded at the apex and tapering at the base, e. g., leaf
oblast. USSR: administrative division within a republic
oblate. layman dedicated to religious life; member of religious community
oblation. offering; offering of bread and wine; charitable offering or gift
obligar. one who binds himself by legal contract
obovate. egg-shaped, with narrow end attached to stalk
obscurant. one who deliberately opposes intellectual advancement and reform; characteristic of an adolescent
obscurantism. deliberately withholding news from the public; an art style
obsequy funeral rite
obtest. supplicate, entreat, adjure, 
obtund. to make less intense, dull (hebetate?)
obturator. one that closes or obstructs; something that closes an opening in the body; a prosthetic device serving the same purpose
obvert. to present another side; to alter the appearance of
occipital bone. curved, trapezoidal, compound bone that forms the lower back of the skull
occiput. back of skull (occipital area)
occlusal. of or pertaining to occlusions of the teeth
oceanid. any of the daughters of Oceanus and Tethys
ocellus. small simple eye found in many invertebrates; an eye-like marking
ochlocracy. mob rule
ochlophobia. demophobia (fear of crowds)
ocotillo. a cactus-like Mexican tree
ocrea. sheath of stipules enclosing the leafstalks of certain plants
octandrious. Having 8 stamens
octenniel. every 8 years
octavo. page size, 5" X 8" to 6" X 9.5" of a book composed of printer's sheets folded into 8 leaves, originally printed on one side of each page
octodecimo. 4" X 6.5", 18 leaves or 36 pages.
octoploid. having 8 haploid sets of chromosomes
octoroon. 1/8th African
octrol. a local tax levied on certain items brought into European countries
odalisque. a female slave or concubine in a harem
odd-pinnate pinnate, with a single unpaired leaflet at the end of the leafstalk
odeum. a small Greek/Roman building for public performances of music and poetry; a contemporary theater or concert hall
odograph. records speed and distance traveled
odonate. dragonflies and damselflies: two pairs of membranous wings, large eyes
odontoblast. tooth cell in surface of dental pulp that produces dentine
odontoid. resembles a tooth
odontoid process. small tooth-like projection from second vertebra of neck around which the first vertebra rotates
odontology. anatomy, growth, and diseases of the tooth
odontophore. a protrusile structure at the base of the mouth of most mollusks, supporting the radula
oenology. the study of wines
oenomel. beverage of ancient Greece consisting of wine and honey
oeuvre. the sum of an artist's life work
ofay. a honky
offal. rubbish
officient. one who officiates at a religious service; celebrant
officiary. body of officials or officers; an official; having a title (used of a dignitary)
officinal. a drug available with a prescription; medical plant
offing. that part of the sea that is distant yet seen from the shore
off-putting. tending to disconcert or repel
off-scouring. something that is scoured off: a social misfit or outcast
ogee. curve or molding like integral sign; arch of two curves meeting at a point
ogham. 6th C. Irish writing alphabet
ogive. diagonal rib of Gothic arch; a pointed arch; cumulative frequency distr.
Oglala. Teton Dakota group
ogress. a lady ogre
oidium. thin-walled fungal spore
okapi. like a giraffe but short neck and smaller
old-man-and-woman. house leek
old--man cactus. tree-like cactus with tufts of long white hair on branch tips
old-man's-beard. Spanish moss and virgin's bower
oleander. poisonous evergreen shrub
oleaster. fragrant small Eurasian tree with silvery-green leaves and olive-like fruit
oleograph. chromolithograph imitating an oil painting; lace-like oil patterns on water
oleum. sulfer trioxide in sulfuric acid (corrosive)
oligochaete. earthworms, et al
oligoclase. plagioclase
oligocythemia. cellular blood deficiency, causing anemia
oligogene. gene that determines major qualitative hereditary characteristics
oligomer. polymer consisting of two, three, or four monomers
oligophagous. feeding on a limited variety of foods
oligophrenia. mental deficiency
oligopoly.. too few sellers
oligopsony. too few buyers
oligotropic. lacking in plant nutrients, with an abundance of dissolved oxygen (lake)
oli. heavily spiced stew; medley; musical medley; burlesque entracte
olivary. shaped like an olive' oval bodies on either side of the medulla oblongata
olivenite. copper arsenate
olivine. iron and Mg silicate, used as refractory and in cements
olla podidra. highly seasoned meat and vegetable stew; assorted mixture (olio?)
Olympiad. the 4 years between Olympics; celebration of modern Olympic Games
omasum. the third stomach of a ruminant (as compared to abomasum)
ombre. 40-card card game
ommatidium. one eye element in a bug's eye
omatophore. movable stalk with eye (snails)
omnium gatherum. hodge-podge
omphalos. navel; central part, focal point
onager. wild ass; medieval stone-propelling siege engine
onanism. masturbation; coitus interruptus; self-gratification
oneiric. pertaining to dreams
oneiromancy divination by dreams
onomastics. study of specialized vocabularies; system underlying formation of words
oocyst. encysted form of some sporozoan zygotes
oocyte. a cell, derived from an organism, that undergoes mitosis, produces ovum
oogamete. female gamete of protozoons (gamete: sperm or egg cell)
oogamous. small sperms and larger ova
oogamy. fertilization of oogamous gametes
oogenesis. enlargement and meiosis of an oogonium that produces an ovum
oogonium. one of the cells that form the bulk of ovarian tissue
oolite. small, round, calcareous grain in limestone; limestone composed of oolites
oology. branch of ornithology dealing with bird's eggs
oolong. partly-fermented dark Chinese tea
oophoritis ovarian inflammation
oophyte. stage in plants undergoing metagenesis during which sexual organs appear
oosperm. a fertilized egg
oosphere. a female gamete ready for fertilization
oospore. thick-walled spore
ootheca. egg case of certain insects and mollusks
ootid. one of the four sections into which a mature ovum divides
opacifier. chemical additive making it opaque
opah. large, vividly-colored fish. Edible
op-ed page. personal opinions page
opera bouffe. comic, often satiric, opera
opera comique. has spoken, as well as sung dialogue
operculum. lid like gill flap or horny shell cover in snails; flap like the layer of tissue over an erupting tooth
operon. cluster of proximate genes churning out related enzymes under control of remote gene
operose. involving great labor; laborious; industrious
ophidian. relating to snakes
ophidiology. study of snakes
ophite. green rocks such as diabase, serpentine
Ophiuchus. equatorial constellation
opthalmia. inflammation, especially conjunctivitis
opisthobranch. gills, little or no shell, two pairs of tentacles
opisthoganous. receding jaws
opsin. protein constituent of rhodopsin
opsonin. substance in blood that makes bacteria susceptible to phagocytosis
optative. expressing a wish; optative mood
optic chiasma. partial decussation of optic nerve fibers on bottom of hypothalamus
opuntia. cactus
opuscule. a minor opus
oquassa. freshwater fish
orach. like spinach
oratory. place for prayer, like a private chapel
orc. killer whale
orchidaceous. characteristic of orchids; suggesting ostentatious luxury, showy
orchil. lichen yielding dye
orchis. orchids: magenta, white, or magenta-and-white
Orcus. Hades; Pluto
ordo. annual calendar with instructions for Mass and office for each day
ordonnance. arrangement of elements in a literary or artistic composition or an architectural plan
oread. a mountain nymph
oreide. oroide
Orestes. son of Agamamnon and Clymenestra who, his sister, Electra, avenged his father by slaying his mother and Aegisthus
organdy. transparent, crisp fabric used for trim, curtains, & light apparel
organelle. a specialized part of a cell that acts like an organ
organ of Corti. specialized structure located on the inner surface of the basilar membrane of the cochlea that contains the sensory receptors that respond to sound
organoleptic. perceived by a sensory organ.
organon.  set of principals or methods used in scientific research
organotropism attraction of certain chemicals or microorganisms to certain organs of the body
organum. types of polyphonic music from 9th to 13th C's.
organza. sheer, stiff fabric used for trimming or evening dresses
organzine. a raw-silk thread, usually a warp thread
orgeat. sweet orange and almond used in cocktails and food
oribi. small African antelope
oriel. projecting bay window supported with corbel or bracket.
oriflamme. inspiring standard or symbol; orange-red flag of the Abbey of St. Denis, used as standard by the early kings of France
origami. paper-folding
orison. prayer
orlop. lowest deck of a ship, especially a warship 
ormer. an abalone shell
orlulu. oroide; used to decorate furniture, moldings, etc.
ornithosis. like psittacosis. infecting domestic fowl, transmissible to man
orogeny. mountain-building by folding and faulting of the earth's crust
orography. study of physical properties of mountains
orology. study of mountains
orotund. sonorous
oroide. fake gold used in imitation-gold jewelry
Orphic. mystical or occult; capable of casting a charm or spell; ideas set forth in Orpheus' poems
Orphism. ancient Greek mystery religion arising in 6th C. B. C. from a synthesis of pre-Hellenic beliefs with the Thracian cult of Zagreus and soon becoming entangled with the Eleusinian mysteries and the doctrines of Pythgoras
orphry. band of elaborate embroidery on front of ecclesiastical garments; elaborate embroidery, especially when made of gold
orpiment. arsenic trisulfide used in tanning and in linoleum manufacture
orpine. plant
Orpington. chicken
orris. Iris with fragrant rootstock
orris root. guess! Used in perfumery
ort. a small scrap of food; a scrap, a bit
orthocephalic. skull height/skull length = 0.7 to 0.75
orthoclase. feldspar
orthoclastic. having right-angled cleavage
orthoepy. 1. The study of the pronunciation of words; 2. Customary pronunciations
orthogenesis. the theory that evolutionary change is predetermined by the constitution of germ plasm and is independent of external factors;. The theory that all cultures pass through sequential periods in the same order.
orthognathous. having upper and lower jaws the same length
orthomolecular. theory that mental illness is chemical
orthopedics. surgical or manipulative treatment of skeletal disorders
orthopsychiatry. treatment of incipient and borderline mental disorders, esp., their development in the young
orthoopteran. membranous folded hind wings covered by leathery forewings: locusts, roaches, crickets, and grasshoppers
orthorhombic. three mutually perpendicular axes of different lengths
orthoscope. examines eye through a layer of water compensating for curvature of cornea
orthoscopic. giving undistorted vision
orthotropous. growing straight, so that the micropyle is opposite the stalk
orthostichous. characterized by parallel arrangement in a vertical row
orthotics. branch of medicine that uses prosthetics to support weakened limbs
orthotropic. growing along a vertical axis
ortolan. small, brownish bird eaten as a delicacy (like beccafico); bobolink and sora
os.  mouth or opening like a mouth
os. a bone
os. an esker
oscine. passerine birds that include most songbirds
oscitancy. yawning; drowsy or inattentive
osculant. intermediate between two taxonomic groups; closely adhering, embracing
osculate. osculant
osculation. kiss; point where two branches of a curve share, follow a common tangent
osculum. opening in sponge for expelling water
osier. willows with rod-like twigs used in basketry
Osiris. annual death and resurrection personified nature
osmic. osmium compound
osmometer. measures osmotic pressure
osmunda. fern roots used for potting
osnaburg. grain-sack, upholstery, diaper cotton fabric
ossein. gelatinous bone residue used for gelatin and glue
ossa. plural of os
ossia. direction to performer to designate an alternative passage
Ossian. legendary 3rd century Gaelic hero and bard
ossicle. small bone, especially of the inner ear (incus, malleus, ans stapes)
ossifrage. lammergeier; osprey
osso buco. braised veal shanks in white wine
ossuary. container for holding the bones of the dead
osteal. bone or skeleton
osteitis.  bone inflammation
ostensorium. a monstrance (receptacle for Eucharist)
ostioctasis. surgical fracture of a bone to reset it.
osteoclast. an instrument used in osteooctasis; a large, multinuclear cell that resorbs bony tissue in osteoclsis
osteoid. resembling bone
osteoma. benign bony tumor, especially in skull
osteomalacia. softening of skull because of calcium deficiency
osteomyelitis. inflammation of bone marrow
osteophyte. small abnormal bone growth
ostiary. one who is ordained in the lowest minor orders; a church doorkeeper
ostinato. short melody or phrase that is constantly repeated in the same pitch
ostiole. a small opening or pore
ostium. same thing
ostracod. minute freshwater crustaceans with bivalve carapace
Ostragoth. 493 to 555
otic. pertaining to the ear, auricular
otiose. lazy; useless; ineffective, futile
otitis. ear inflammation
otocyst. auditory capsule in an embryo
otorhinolaryngology. ear, nose, and throat specialist
ottava. octave higher than indicated
ottavarima. stanza with eight 11-syllable lines in iambic pentameter. Rhyme scheme: abababcc
ottoman. low sofa or cushioned footstool; heavy rayon fabric with corded texture
ouabain. used for poison darts in Africa
oubliette. dungeon with trap door in ceiling as only exit
out-and-outer. person who goes to extremes
outface. stare down, overcome with self-assured look
outfall. drain discharge
outlier. house lies far from place of business; outlying rock
outtake. film scene dropped in final version
outturn. output
outwork. fortification beyond main defensive position
ouzel. European bird; water ouzel
ouzo. aniseed-flavored Greek liqueur
overage. surplus
overblow. blow a wind instrument to produce an overtone instead of the fundamental
overdominance. heterozygote has phenotype that is better adapted than either homozygote
overlie. to kill by lying upon
overshot. upper part protruding beyond the lower; overshot water wheel
ovine. pertaining to sheep
ovipositor. tubular structure with which insects lay eggs
ovisac. ootheca or Graafian follicle
ovoto. rounded convex molding (quarter-round)
ovonic. Ovshinsky effect
ovoviviparous. eggs hatch within females body
Ovshinsky effect. glossy film switches from nonconductor to semi-conductor upon application of a minimum voltage
ovule. immature ovum; minute structure which, after fertilization, becomes a plant seed
oxalia. flowers
oxbow. ox yoke; bend in river; land enclosed by an oxbow
ox-eye. daisy-like plants; round or oval dormer window
oxidative phosphorylation. intracellular respiration within mitochondria, forming ATP
oxlip. Eurasian primrose
oxpecker. African birds that feed upon ticks on hides of large animals
oxycephaly. congenital. Skull assumes a conical shape.
oxytocic. induces childbirth
oxytone. stress or acute accent on last syllable
oxyuriasis. pinworm infestation
eyer and terminer. hearing and trial; high criminal court in some states
oyster-catcher. black-and-white shore birds with long orange-red bills
oyster crab. lives inside oyster shells
oysters Rockefeller. spinach and cream sauce
ozocerite.. yellow-brown, black, or green hydrocarbon wax used in making electrical insulators, lubricants, and inks
ozonide.. various, often explosive, chemicals created by attaching ozone to an unsaturated compound. Used to locate such bonds
ozonize.. impregnate with ozone. Create ozone.