What does "knuckle down" mean?

To start working hard and seriously To focus and apply oneself diligently.

How do you use "knuckle down" in a sentence?

Time to knuckle down and study. We need to knuckle down and finish this. She finally knuckled down.

Phrasal Verb BritishAmericanAustralian ★★★☆☆ Moderate Neutral

Meaning: To start working hard and seriously

开始认真努力

Ponerse manos a la obra en serio

本腰を入れて取り組む

본격적으로 열심히 하다, 각오를 다지다

To focus and apply oneself diligently.

集中精力、勤奋地投入工作或学习。暗示之前可能不够认真，现在要严肃对待。

Empezar a trabajar con seriedad y dedicación. Implica que antes no se estaba poniendo todo el esfuerzo necesario.

真剣に集中して仕事や勉強に取り組み始めること。遊びをやめて本気になるニュアンス。

집중하여 성실하게 임하는 것.

Base verb: knuckle

Particle: down

Separable: No — the verb and particle stay together

Time to knuckle down and study.
该认真学习了
Es hora de ponerse a estudiar en serio
本腰を入れて勉強する時だ
본격적으로 공부할 시간이야.
We need to knuckle down and finish this.
我们得埋头苦干把这个完成
Tenemos que ponernos las pilas y terminar esto
本気で取り組んでこれを終わらせないと
본격적으로 매달려서 이걸 끝내야 해.
She finally knuckled down.
她终于开始认真了
Por fin se puso a trabajar en serio
彼女はついに本気になった
그녀가 드디어 본격적으로 시작했다.

Context: focus, determination

Tone: serious

Possibly from pressing knuckles down to work.

Era: Modern

Generation: All ages

Social background: Universal