πρόλογος

English (LSJ)

ὁ, in early Trag. and Com.,

   A prologue of a play, i.e. the part before the entry of the chorus, Arist.Po. 1452b19; esp. (as in E.) monologue containing a narrative of facts introductory to the main action, Ar.Ra.1119, etc., cf. Arist.Rh.1414b20.    2 one who speaks the prologue, Luc.Pseudol.4.    3 introduction in a speech, Lib.Or.1.55(pl.), al.    II Arith., antecedent, in ratios in which the first number is the largest, as 5:3, Nicom.Ar.1.19, Theol.Ar.13, Dam.Pr.374; cf. ὑπόλογος.