Lewis & Short

ternārĭus, a, um, adj. [terni], containing or consisting of three, ternary.

  1. I. Adj.: scrobes, i. e. of three feet, Col. 11, 2, 28: numerus, Aus. Idyll. 11 praef.
  2. II. Subst.: ternārĭus, ii, m., for triens, a third of an as, Pelag. Vet. 16.