slit / slit/ • n. a long, narrow cut or opening: make a slit in the stem under a bud | arrow slits.• v. (slit·ting; past slit) [tr.] make a long, narrow cut in (something): give me the truth or I will slit your throat | [tr.] he slit open the envelope. ∎ cut (something) into strips: a wide recording head magnetizes the tape before it is slit to domestic size. ∎ (past slit·ted) form (one's eyes) into slits; squint.DERIVATIVES: slit·ter n.