whack

UK: /ˈ^hwæk/ US: /hwæk, wæk/ ,(hwak, wak)

WordReference Random House Learner's Dictionary of American English © 2025

whack /hwæk, wæk/   v. 

1. to strike or hit with or as if with a strong, loud blow: [~ + object]
   She whacked the stick against the table.
   [no object]
   He whacked at the ball and missed.

n. [countable]

2. a smart, resounding blow:
   She gave him a whack on the knuckles.
3. Informal Terms an attempt:
   He took a whack at the job.

Idioms

4. Idioms, Informal Terms out of whack, out of order;
   not working correctly or properly.

whack•er, n. [countable]

WordReference Random House Unabridged Dictionary of American English © 2025

whack  (hwak, wak), v.t. 

1. to strike with a smart, resounding blow or blows.
2. Slang Terms to divide into or take in shares (often fol. by up):
   Whack the loot between us two.

v.i. 

3. to strike a smart, resounding blow or blows.
4. whack off:
   • to cut off or separate with a blow:
     The cook whacked off the fish's head.
   • Slang (vulgar). to masturbate.
5. Slang Terms whack out, to produce quickly or, sometimes, carelessly:
   She whacks out a short story every week or so.

n. 

6. a smart, resounding blow:
   a whack with his hand.
7. Informal Terms a trial or attempt:
   to take a whack at a job.
8. Slang Terms a portion or share.
9. Informal Terms out of whack, out of order or alignment;
   not in proper condition.

• 1710–20; origin, originally dialect, dialectal, Scots form of thwack; compare whang², whittle

whack′er, n. 
Synonyms

• 7. try, go, turn.

Collins Concise English Dictionary © HarperCollins Publishers::

whack / wæk/ verb (transitive)

1. to strike with a sharp resounding blow
2. (usually passive) to exhaust completely
3. (tr; usually followed by in or on) to put something on to or into something else with force or abandon: whack on some sunscreen
4. (transitive) to murder: if you were out of line you got whacked

noun

1. a sharp resounding blow or the noise made by such a blow
2. a share or portion
3. a try or attempt (esp in the phrase have a whack at)
4. out of whack ⇒ out of order; unbalanced: the whole system is out of whack

Etymology: 18th Century: perhaps a variant of thwack, ultimately of imitative origin

ˈwhacker noun