[prot.a.sis] n, pl -a.ses [LL, fr. Gk, premise of a syllogism, conditional clause, fr. proteinein to stretch out before, put forward, fr. pro- + teinein to stretch--more at thin] (ca. 1568) 1: the introductory part of a play or narrative poem
2: the subordinate clause of a conditional sentence--compare apodosis -- pro.tat.ic adj