What does whack mean?
Whack is a blunt, informal word that most immediately means a sharp strike. As a verb, it describes hitting something with force, and in American English it is sometimes used euphemistically for killing by a violent blow. As a noun, a whack can be the blow itself or its sound; it can also mean an informal attempt, as in taking a run at a task. In chiefly British usage, the noun can denote a sharp increase, especially in taxes or charges. The phrase out of whack uses the word to mean disordered or malfunctioning. Although the vocabulary is conversational rather than formal, whack is useful because it shifts readily between literal violence, comic exaggeration, and figurative effort.
To strike someone or something with a sharp, forceful blow; informally, to kill by means of such a blow.
"He whacked the post with the heel of his boot."
The killing sense is informal and often euphemistic. The word can also be used comically for an especially forceful strike.
A sharp blow or the sound of one; an informal attempt; or, chiefly in British usage, a sharp increase in a price, tax, or charge.
"The old machine started after a couple of sharp whacks."
The attempt and increase senses are informal, while the literal blow sense is common in both speech and narrative writing.
Disordered, damaged, or not functioning properly, chiefly in the phrase out of whack.
"The clock is out of whack and is losing several minutes a day."
This is chiefly a predicative use in the established phrase out of whack.
The regular plural is used for individual blows or instances of striking.
"The post absorbed several whacks from the axe before it split."
Whack packs three ideas into one blunt syllable: a blow, the sound of a blow, and informal permission to give it a try.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does whack come from?
Whack is generally treated as a variant spelling of thwack. The pair is associated with the sound of a sharp blow, reflecting an imitative development within English rather than a borrowing from another language. The change from thwack to whack represents a simplification of the initial consonant cluster while retaining the word's abrupt, forceful character.
Related word forms
How whack is actually used
Whack is predominantly informal and often blunt, comic, or exaggerated. The sense meaning to kill is especially associated with American usage and may be euphemistic or jocular. The noun meaning a sharp increase is chiefly British.
Easily confused with whack
Whack is the standard spelling for a blow or an informal attempt, whereas wack is chiefly a variant spelling and is also used as a separate informal word meaning eccentric or crazy.
Thwack is an older alternative spelling associated with the same striking sense, but whack is the usual modern form.