Quash \Quash\, v. t. [imp. & p. p. {Quashed}; p. pr. & vb. n. {Quashing}.] [OF. quasser, F. casser, fr. L. cassare to annihilate, annul, fr. cassus empty, vain, of uncertain origin. The word has been confused with L. quassare to shake, F. casser to break, which is probably of different origin. Cf. {Cashier}, v. t.] (Law) To abate, annul, overthrow, or make void; as, to quash an indictment. --Blackstone.