Orange Free State
— Noun
– English
～ a province in central South Africa that was colonized by the Boers; named Free State in 1997
Old Line State
— Noun
– English
～ a Mid-Atlantic state; one of the original 13 colonies
Old North State
— Noun
– English
～ a state in southeastern United States; one of the original 13 colonies
Old Dominion State
— Noun
– English
～ a state in the eastern United States; one of the original 13 colonies; one of the Confederate States in the American Civil War
Ocean State
— Noun
– English
～ a state in New England; one of the original 13 colonies; the smallest state
oxidation state
— Noun
– English
～ the degree of oxidation of an atom or ion or molecule; for simple atoms or ions the oxidation number is equal to the ionic charge; "the oxidation number of hydrogen is +1 and of oxygen is -2"