crack

When something cracks it breaks along a line, maybe not a straight line. It might break into two pieces, or it might break but the two pieces are still attached.

Example: She cracked an egg and put the inside of the egg into a bowl.

A crack is the line where something is breaking.

Example: There is a crack from the edge of this plate to the middle. It will break soon.

A loud sound like the sound of something breaking.

Example: It was raining, and she saw a flash of lightning and heard the crack of thunder.

A strong, fairly cheap form of cocaine; crack often comes in the form of a rock and it is usually smoked in a crack-pipe.

Example: "I wouldn't use it, if I was going to use it I can afford real cocaine. Crack is wack." - Whitney Houston