n. 1 break, fracture, chink, crevice, rift, gap, flaw, split, fissure, slit, cleft, split, check, rupture, breach The crack in the dam was caused by an earthquake 2 snap, report, bang, clap, shot I ducked when I heard the crack of the rifle 3 moment, instant, time, second She gets up at the crack of dawn
v. 4 snap He cracks the whip and the horses start up 5 break, fracture, rupture; shiver, shatter, smash He fell backwards on the pavement and cracked his skull 6 fissure, craze, crackle, US alligator The heat of the sun caused the paint to crack