Squeal \Squeal\, v. i. [imp. & p. p. {Squealed}; p. pr. & vb. n. {Squealing}.] [Of Scand. origin; cf. Sw. sqv["a]la, Norw. skvella. Cf. {Squeak}, {Squall}.] 1. To cry with a sharp, shrill, prolonged sound, as certain animals do, indicating want, displeasure, or pain. 2. To turn informer; to betray a secret. [Slang]