o

the blood group whose red cells carry neither the A nor B antigens; "people with type O blood are universal donors" ; the 15th letter of the Roman alphabet ; 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'brien

Irish writer (born in 1932) ;

o'casey

Irish playwright (1880-1964) ;

o'connor

United States writer (1925-1964) ;

o'flaherty

Irish writer of short stories (1896-1984) ;

o'hara

United States writer (1905-1970) ;

o'keeffe

United States painter (1887-1986) ;

o'neill

United States playwright (1888-1953) ;

o'toole

British actor (born in Ireland in 1932) ;

o. henry

United States writer of short stories whose pen name was O. Henry (1862-1910) ;

o.e.d.

an unabridged dictionary constructed on historical principles ;

o.k.

an endorsement; "they gave us the O.K. to go ahead" ;

o level

the basic level of a subject taken in school ;

o ring

a gasket consisting of a flat ring of rubber or plastic; used to seal a joint against high pressure ;

oaf

an awkward stupid person ;

oahu

an island of central Hawaii (between Molokai and Kauai); the chief island of the state ;

oahu island

an island of central Hawaii (between Molokai and Kauai); the chief island of the state ;

oak

a deciduous tree of the genus Quercus; has acorns and lobed leaves; "great oaks grow from little acorns" ; the hard durable wood of any oak; used especially for furniture and flooring ;

oak-leaved goosefoot

annual European plant with spikes of greenish flowers and leaves that are white and hairy on the underside; common as a weed in North America ;

oak apple

oak gall caused by larvae of a cynipid wasp ;

oak blight

a black plant louse that lives on oaks and dogwoods ;

oak chestnut

a tree of the genus Castanopsis ;

oak fern

bright blue-green fern widely distributed especially in damp acid woodlands of temperate northern hemisphere ;

oak leaf cluster

a United States military decoration consisting of bronze or silver oak leaves and acorns awarded to anyone who has won a given medal before ;

oak tree

a deciduous tree of the genus Quercus; has acorns and lobed leaves; "great oaks grow from little acorns" ;

oakland

a city in western California on San Francisco Bay opposite San Francisco; primarily and industrial urban center ;

oakleaf goosefoot

annual European plant with spikes of greenish flowers and leaves that are white and hairy on the underside; common as a weed in North America ;

oakley

United States sharpshooter who was featured in Buffalo Bill's Wild West Show (1860-1926) ;

oakum

loose hemp or jute fiber obtained by unravelling old ropes; when impregnated with tar it was used to caulk seams and pack joints in wooden ships ;

oar

an implement used to propel or steer a boat ;

oarfish

thin deep-water tropical fish 20 to 30 feet long having a red dorsal fin ;

oarlock

a holder attached to the gunwale of a boat that holds the oar in place and acts as a fulcrum for rowing ;

oarsman

someone who rows a boat ;

oarsmanship

skill as an oarsman ;

oarswoman

a woman oarsman ;

oas

an association of countries in the western hemisphere; created in 1948 to promote military and economic and social and cultural cooperation ;

oasis

a shelter serving as a place of safety or sanctuary ; a fertile tract in a desert (where the water table approaches the surface) ;

oast

a kiln for drying hops ;

oast house

a building containing an oast (a kiln for drying hops); usually has a conical or pyramidal roof ;

oat

seed of the annual grass Avena sativa (spoken of primarily in the plural as `oats') ; annual grass of Europe and North Africa; grains used as food and fodder (referred to primarily in the plural: `oats') ;