- Proceeding by threes; consisting of three; as, the ternary
number was anciently esteemed a symbol of perfection, and held in great
veneration. - 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; thus, sodic
hydroxide, NaOH, is a ternary compound. - A ternion; the number three; three things taken together;
a triad.