Lewis & Short

quăternārĭus, a, um, adj. [quaterni], consisting of four each, containing four, quaternary (post-Aug.): scrobes quaternarii, hoc est quoquoversus pedum quattuor, four feet square, Col. 11, 2, 28: numerus, the number four, the quaternary, Plin. 28, 6, 17, § 64: formae, of coins, Lampr. Alex. Sev. 38.