smack

A sharp blow, typically with an open hand.

"He gave the dog a light smack."

To hit someone or something with an open hand, often as punishment.

"She smacked the child's bottom."

To open and close one's lips loudly, often showing enjoyment of food.

"He smacked his lips after the meal."

An informal, slang term for the illegal drug heroin.

"He was addicted to smack."