1. To become fractured; break or crack on the surface only; SYN. check, break.
2. To break partially but keep its integrity.
3. To cause to become cracked.
4. To hit forcefully; deal a hard blow, making a cracking noise.
5. To make a very sharp explosive sound.

1. A long narrow opening; SYN. cleft, crevice, fissure, scissure.
2. A mark left after a small piece has been chopped or broken off of something; SYN. check, chip.
3. A usually brief attempt; SYN. fling, go, pass, whirl, offer.
4. A sudden sharp noise; SYN. cracking.
5. A purified and potent form of cocaine that is smoked rather than snorted.

Street name for a chemical derivative (bicarbonate) of cocaine in hard, crystalline lumps; it is heated and inhaled (smoked) as a stimulant. Crack was first used in San Francisco in the early 1980s, and is highly addictive.
Its use has led to numerous deaths but it is the fastest-growing sector of the illegal drug trade, since it is less expensive than cocaine.

Of superior excellence or ability

1. To gain unauthorized access to a network by breaching its security.
2. To decipher encrypted information.