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Words starting with o

Word Definition
O 1. O, the fifteenth letter of the English alphabet, derives its form, value, and name from the Greek O, through the Latin. The letter came into the Greek from the Ph/nician, which possibly derived it ultimately from the Egyptian. Etymologically, the letter o is most closely related to a, e, and u; as in E. bone, AS. ban; E. stone, AS. stan; E. broke, AS. brecan to break; E. bore, AS. beran to bear; E. dove, AS. d/fe; E. toft, tuft; tone, tune; number, F. nombre.
2. Among the ancients, O was a mark of triple time, from the notion that the ternary, or number 3, is the most perfect of numbers, and properly expressed by a circle, the most perfect figure.
3. (n.) The letter O, or its sound.
4. (n.) Something shaped like the letter O; a circle or oval.
5. (n.) A cipher; zero.
6. (adj.) One.
7. (interj.) An exclamation used in calling or directly addressing a person or personified object; also, as an emotional or impassioned exclamation expressing pain, grief, surprise, desire, fear, etc.
8. (n.) the blood group whose red cells carry neither the A nor B antigens
9. (n.) the 15th letter of the Roman alphabet
10. (n.) a nonmetallic bivalent element that is normally a colorless odorless tasteless nonflammable diatomic gas; constitutes 21 percent of the atmosphere by volume; the most abundant element in the earth's crust
O level 1. (n.) the basic level of a subject taken in school
O ring 1. (n.) a gasket consisting of a flat ring of rubber or plastic; used to seal a joint against high pressure
O. Henry 1. (n.) United States writer of short stories whose pen name was O. Henry (1862-1910)
o.d. 1. (v.) dose too heavily
O.E.D. 1. (n.) an unabridged dictionary constructed on historical principles
O.K. 1. (adj.) being satisfactory or in satisfactory condition
2. (adv.) in a satisfactory or adequate manner; (`alright' is a nonstandard variant of `all right')
3. (n.) an endorsement
4. (v.) give sanction to
O' 1. A prefix to Irish family names, which signifies grandson or descendant of, and is a character of dignity; as, O'Neil, O'Carrol.
2. (prep.) A shortened form of of or on.
O'Brien 1. (n.) Irish writer (born in 1932)
O'Casey 1. (n.) Irish playwright (1880-1964)
o'clock 1. (adv.) according to the clock
O'Connor 1. (n.) United States writer (1925-1964)
o'er 1. (prep.) A contr. of Over.
2. (adv.) throughout a period of time
O'Flaherty 1. (n.) Irish writer of short stories (1896-1984)
O'Hara 1. (n.) United States writer (1905-1970)
O'Keeffe 1. (n.) United States painter (1887-1986)
O'Neill 1. (n.) United States playwright (1888-1953)
O's 1. (n. pl.) of O
O'Toole 1. (n.) British actor (born in Ireland in 1932)
Oad 1. (n.) See Woad.
oaf 1. (n.) Originally, an elf's child; a changeling left by fairies or goblins; hence, a deformed or foolish child; a simpleton; an idiot.
2. (n.) an awkward stupid person
oafish 1. (adj.) Like an oaf; simple.
2. (adj.) ill-mannered and coarse and contemptible in behavior or appearance
Oahu 1. (n.) an island of central Hawaii (between Molokai and Kauai); the chief island of the state
Oahu Island 1. (n.) an island of central Hawaii (between Molokai and Kauai); the chief island of the state
oak 1. (n.) Any tree or shrub of the genus Quercus. The oaks have alternate leaves, often variously lobed, and staminate flowers in catkins. The fruit is a smooth nut, called an acorn, which is more or less inclosed in a scaly involucre called the cup or cupule. There are now recognized about three hundred species, of which nearly fifty occur in the United States, the rest in Europe, Asia, and the other parts of North America, a very few barely reaching the northern parts of South America and Africa. Many of the oaks form forest trees of grand proportions and live many centuries. The wood is usually hard and tough, and provided with conspicuous medullary rays, forming the silver grain.
2. (n.) The strong wood or timber of the oak.
3. (n.) a deciduous tree of the genus Quercus; has acorns and lobed leaves
4. (n.) the hard durable wood of any oak; used especially for furniture and flooring
oak apple 1. (n.) oak gall caused by larvae of a cynipid wasp
oak blight 1. (n.) a black plant louse that lives on oaks and dogwoods
oak chestnut 1. (n.) a tree of the genus Castanopsis
oak fern 1. (n.) bright blue-green fern widely distributed especially in damp acid woodlands of temperate northern hemisphere
Oak Leaf Cluster 1. (n.) a United States military decoration consisting of bronze or silver oak leaves and acorns awarded to anyone who has won a given medal before