Lewis & Short

sup-par (subpar), păris, adj., nearly equal (rare but class.): huic aetati suppares Alcibiades, Critias, * Cic. Brut. 7, 29: aetas, Vell. 1, 17, 1: aevum, Aus. Ep. 1, 13: musicae suppari gressu, App. M. 6, p. 183, 12: fratres, nec similes ejus nec suppares, Amm. 26, 10, 9.
In logic: propositiones suppares, App. Dogm. Plat. 3, p. 31 sq.