What does smack mean?
“Smack” is a versatile word whose central meaning is a sharp, sudden impact: as a noun, it denotes a blow or slap, and as a verb, it means to strike or slap someone in this way. The word can also describe a loud, emphatic kiss, with “smack lips” referring to the sound or action of kissing loudly. In informal drug vocabulary, “a smack” means a small amount of heroin or a similar narcotic. These meanings share an emphasis on abruptness, force, or sensory impact, although the drug sense is separate from the ordinary physical meanings. “Smack” appears naturally in phrases such as “a smack in the face,” “a smack on the back,” and “smack lips.” It is also used figuratively for a forceful verbal blow or criticism. The word is informal in several contexts but remains widely understood in British and American English.
A sharp blow or slap, especially one that makes a sudden sound.
"The door closed with a loud smack."
Also used figuratively for a forceful verbal blow or criticism.
A loud, emphatic kiss.
"She gave him a quick smack on the cheek."
Informal; often expressed in the phrase “smack lips.”
A small amount of heroin or a similar drug.
"The musician's story about a smack was dismissed as exaggeration."
Informal and restricted to drug-related contexts.
To strike or slap someone sharply.
"He smacked the table to get their attention."
The verb is transitive and commonly implies a sharp or noisy action.
The plural is used for individual blows, kisses, or instances of the noun.
"The boxer felt several smacks to the head."
One word can describe everything from a sudden slap to a deliberately loud kiss—and, in street slang, a quantity of heroin.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does smack come from?
The word comes from Middle English and appears in both noun and verb uses. Its origin is associated with the sharp, abrupt sound associated with striking or kissing, and it developed through an imitative sense before acquiring the figurative meanings of forcefulness and emphasis. The modern slang sense for heroin belongs to the broader history of informal drug terminology and is not the original meaning.
Related word forms
How smack is actually used
The senses involving a kiss and heroin are informal or slang; the general sense of a blow is also commonly used figuratively, as in “a smack of bitter criticism.”