submit vs knuckle under

submit and knuckle under both are verbs.

Word	Noun	Adjective	Verb	Adverb
submit	No	No	Yes	No
knuckle under	No	No	Yes	No

As verbs, knuckle under is a hypernym of submit; that is, knuckle under is a word with a broader meaning than submit:

Other hypernyms of submit include buckle under, give in, succumb, yield.

submit (verb)	knuckle under (verb)
accept as inevitable	consent reluctantly
accept or undergo, often unwillingly
put before
refer for judgment or consideration
yield to another's wish or opinion
yield to the control of another
make an application as for a job or funding
hand over formally
make over as a return
refer to another person for decision or judgment