Main Entry: ter·na·ry

Pronunciation: \ˈtər-nə-rē\

Function: adjective

Etymology: Middle English, from Latin ternarius, from terni three each; akin to Latin tres three — more at three

Date: 15th century

1 a : of, relating to, or proceeding by threes b : having three elements, parts, or divisions c : arranged in threes <ternary petals>
2 : using three as the base <a ternary logarithm>
3 a : being or consisting of an alloy of three elements b : of, relating to, or containing three different elements, atoms, radicals, or groups <sulfuric acid is a ternary acid>
4 : third in order or rank