Source : Webster's Revised Unabridged Dictionary (1913)

Prolation \Pro*la"tion\, n. [L. prolatio: cf. F. prolation.]
   1. The act of prolating or pronouncing; utterance;
      pronunciation. [Obs.] --Ray.

   2. The act of deferring; delay. [Obs.] --Ainsworth.

   3. (Mus.) A medi[ae]val method of determining of the
      proportionate duration of semibreves and minims. --Busby.