adjective Containing, or consisting of, three different parts, as elements, atoms, groups, or radicals, which are regarded as having different functions or relations in the molecule.
Sodic hydroxide, NaOH, is a ternary compound.
adjective Of an operator taking three operands.
An "if…then…else" construction is called a ternary operator when it is combined in one line of a program.
noun A group of three things; a trio, threesome or tierce.