1 line on the surface of sth where it has broken
ADJ. big, deep, huge, large, long, serious | short, small | fine, hairline, thin
CRACK + VERB appear | develop, spread | run A fine crack ran up the wall.
2 narrow opening
ADJ. narrow, small, tiny | wide
VERB + CRACK fill We filled the cracks in the plaster before hanging the wallpaper.
CRACK + VERB appear Wide cracks appeared in the ground during the drought. | open up, widen
PREP. ~ in There's a crack in the fence big enough to look through.
PHRASES a crack of light a tiny crack of light under the door | open a door/window a crack Could you open the window just a crack?
3 sudden loud sound
ADJ. loud, sharp
VERB + CRACK give, let out He gave a crack of laughter. | hear
PREP. with a ~ The chandelier hit the floor with a crack. | ~ of
PHRASES the crack of a whip, a crack of thunder > Note at SOUND
ADV. badly The dish had cracked quite badly. | slightly
2 become mentally ill
ADV. completely | finally The stresses of her job became too great and she finally cracked. | up He thought he'd never get through the ordeal without cracking up.
PHRASES crack under the pressure/strain, show signs of cracking He is under a lot of pressure but is showing no signs of cracking. PHRASAL VERBS crack down
PREP. on to crack down hard on crime