Soothsay \Sooth"say`\, v. i. [Sooth + say; properly to say truth, tell the truth.] To foretell; to predict. ``You can not soothsay.'' --Shak. ``Old soothsaying Glaucus' spell.'' --Milton. Soothsay \Sooth"say`\, n. 1. A true saying; a proverb; a prophecy. [Obs.] --Spenser. 2. Omen; portent. Having God turn the same to good soothsay. --Spenser.