The Collaborative International Dictionary of English v.0.48:
Soothsayer \Sooth"say`er\, n. 1. One who foretells events by the art of soothsaying; a prognosticator. [1913 Webster] 2. (Zool.) A mantis. [1913 Webster]WordNet (r) 3.0 (2006):
soothsayer n 1: someone who makes predictions of the future (usually on the basis of special knowledge) [syn: forecaster, predictor, prognosticator, soothsayer]