o
- 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
- n the 15th letter of the Roman alphabet
- n the blood group whose red cells carry neither the A nor B antigens
people with type O blood are universal donors
o. henry
- n United States writer of short stories whose pen name was O. Henry (1862-1910)
o.e.d.
- n an unabridged dictionary constructed on historical principles
o ring
- n a gasket consisting of a flat ring of rubber or plastic; used to seal a joint against high pressure
oahu
- n an island of central Hawaii (between Molokai and Kauai); the chief island of the state
oahu island
- n an island of central Hawaii (between Molokai and Kauai); the chief island of the state
oak
- n the hard durable wood of any oak; used especially for furniture and flooring
- n a deciduous tree of the genus Quercus; has acorns and lobed leaves
great oaks grow from little acorns
oak-leaved goosefoot
- n 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