From Academic Kids
It has a charge of −1. Hydroxide is one of the simplest of the polyatomic ions.
The term hydroxyl group is used to describe the functional group -OH when it is a substituent in an organic compound. Organic molecules containing a hydroxyl group are known as alcohols (the simplest of which have the formula CnH2n+1-OH).
A group of bases containing hydroxide are called hydroxide bases. Hydroxide bases will dissociate into a cation and one or more hydroxide ions in water, making the solution basic.
Hydrogen hydroxide is another name for water, as is hydrohydroxic acid. Both names are based on the hydroxide ion.