Hydroxide

H-O^-

It has a charge (oxidation number) of -1 unit.

The term hydroxyl group is used when the functional group -OH is counted as a substituent[?] of an organic compound. Organic molecules containing a hydroxyl group are known as alcohols.

Hydroxide is one of the simplest of the polyatomic ions. Hydroxide is a general term for any salt containing stoichiometric amounts of this polyatomic ion.