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knuckle - definition and synonyms


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verb knuckle pronunciation in British English /ˈnʌk(ə)l/
Word Forms
present tense
present participleknuckling
past tenseknuckled
past participleknuckled
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phrasal verbs

knuckle down

Word Forms
present tense
I/you/we/theyknuckle down
he/she/itknuckles down
present participleknuckling down
past tenseknuckled down
past participleknuckled down
to start working hard, especially when you should have done this earlier
It’s time you knuckled down to some work.

knuckle under

Word Forms
present tense
I/you/we/theyknuckle under
he/she/itknuckles under
present participleknuckling under
past tenseknuckled under
past participleknuckled under
to do what someone tells you to do
He wasn’t going to knuckle under to some woman.


a course of study which is much shorter than a university course and focuses on the skills you need for a job, especially computer-related skills

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a stupid person

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an ancient Roman system of underfloor heating, used to heat houses with hot air; from the Latin 'hypocaustum'

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