Word.ws English Dictionary

knuckle up

knuckle up verb: to clench one's fist(s) as though in preparation for a fight.

Verb

knuckle up (third-person singular simple present knuckles up, present participle knuckling up, simple past and past participle knuckled up)

  1. (informal, chiefly African-American Vernacular) To clench one's fist(s) as though in preparation for a fight.
    • With a resolve to get his son away from these monsters, Isaac knuckled up and mean-mugged his opponent.2012, Vanessa Miller, Latter Rain
    • Tony stumbled a little and when he found his balance, he knuckled up and sent a jab toward Will's neck.2012, Pink Maxwell, A Scorpion's Sting, page 209
  2. (broadly, informal) To approach a problem aggressively.
  3. (slang) To strike or fight.

Forms of knuckle up

third-person singular presentknuckles up
present participleknuckling up
past participleknuckled up
pastknuckled up

Questions about knuckle up

What does knuckle up mean?
Knuckle up means to clench one's fist(s) as though in preparation for a fight.
What part of speech is knuckle up?
Knuckle up is a verb.
What is the past tense of knuckle up?
The past tense of knuckle up is knuckled up.

Words near knuckle up in the dictionary

  1. knuckle joints
  2. knuckle sandwich
  3. knuckle sandwiches
  4. knuckle to
  5. knuckle under
  6. knuckle up
  7. knuckle-buster
  8. knuckle-busters
  9. knuckle-dragger
  10. knuckle-draggers
  11. knuckle-dragging

Source and license

Adapted from Wiktionary: knuckle up (page history and authors). Text available under the Creative Commons Attribution-ShareAlike 4.0 license. Word.ws reformatted the entry and added links. Wiktionary data of 2026-09-02.

Last updated:

Cite this entry: “knuckle up.” Word.ws, https://word.ws/knuckle_up. Based on Wiktionary, CC BY-SA 4.0.