verb (used with object), knuck·led, knuck·ling.
- to apply oneself vigorously and earnestly; become serious: Just knuckle down for an hour or so and finish the work.
- Also knuckle under. to submit; yield.
Origin of knuckle
Related formsknuck·ly, adjective
British Dictionary definitions for knuckle under (1 of 2)
British Dictionary definitions for knuckle under (2 of 2)
Derived Formsknuckly, adjective
Word Origin for knuckle
Medicine definitions for knuckle under
Idioms and Phrases with knuckle under (1 of 2)
Also, knuckle down. Give in, acknowledge defeat, as in The dean refused to knuckle under to the graduate students' demands, or He was forced to knuckle down before their threats of violence. Presumably this idiom alludes to a kneeling position with hands on the ground, knuckles down. [Mid-1700s]
Idioms and Phrases with knuckle under (2 of 2)
In addition to the idioms beginning with knuckle
- knuckle down
- knuckle under
- rap someone's knuckles