English Reference
Idiom idiom

knuckle down


To get to work; to focus on a task.

Meaning adapted from Wiktionary, available under CC BY-SA 4.0.


SIMPLE

I need to knuckle down and finish my homework.

CONTEXTUAL

With the final exams approaching next week, the students decided to knuckle down and study in the library.

COMPLEX

Recognizing that the project deadline was rapidly approaching, the team finally knuckled down to resolve the remaining technical challenges.


first recorded 19th c.

First attested in 1864 in American English, the phrase originates in the game of marbles. The expression refers to the requirement that a player place their knuckles firmly on the ground before shooting.


Related idioms2entries
  1. 01

    knuckle dragger

    A large, strong, and rather dimwitted person.

  2. 02

    knuckle under

    To cooperate or yield when forced or pressured to do so.

Last updated August 10, 2026