verb
To make or become cracked
split, fracture, shatter, craze; see break 1, 2, 3.
To make a noise of something breaking
snap, crackle, bang, crash; see sound 1.
To damage
injure, hurt, impair; see damage 1.
*To lose mental control
break down, go to pieces, succumb, go crazy; see crack up 2, weaken 1, yield 1.
To solve
figure out, answer, decipher, decode; see solve. See syn. study at break.
get cracking*