- 1 [countable] a sharp hit given with your open hand, especially to a child as a punishment You'll get a smack on your backside if you're not careful.
- 2[countable] (informal) a hard hit given with a closed hand synonym Punch a smack on the jaw
- 3[countable, usually singular] a short loud sound She closed the ledger with a smack.
- 4[countable] (informal) a loud kiss a smack on the lips/cheek
- 5 [uncountable] (slang) the drug heroin smack addicts