(1):
(a.) Proceeding by threes; consisting of three; as, the ternary number was anciently esteemed a symbol of perfection, and held in great veneration.
(2):
(a.) 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.
(3):
(n.) A ternion; the number three; three things taken together; a triad.