Late Middle English; earliest use found in John Gower (d. 1408), poet. From Middle French prolacion, Middle French, French prolation utterance, action of uttering or declaring, delay, emission of the divine Word and its etymon classical Latin prōlātiōn-, prōlātiō fact or action of putting forward examples in support of a case, enlargement, extension, postponement, delay, in post-classical Latin also utterance, pronunciation (Vetus Latina), the sending forth or emission of the divine word (late 2nd cent. in Tertullian), production, creation, (in medieval music) relative duration or time value of a minim to a semibreve from prōlāt-, past participial stem of prōferre to bring forth, to produce, to utter, pronounce, to prolong, extend + -iō.