knuckle under

• POS: Verb (intransitive)
• HYPHEN: knuck=le un=der

CIDE DICTIONARY

knuckle under, v. i. 

 To yield; to submit; -- usually used with to.  [PJC]

THESAURUS

knuckle under

accede, accept, acquiesce, assent, be agreeable, bow, capitulate, cave, comply, consent, defer, face the music, go along with, knock under, knuckle, knuckle down, live with it, not resist, obey, relent, resign, submit, succumb, swallow it, swallow the pill, take, take it

ROGET THESAURUS

knuckle under

Submission

VB succumb, submit, yeild, bend, resign, defer to, lay down one's arms, deliver up one's arms, lower colors, haul down colors, strike one's flag, strike colors, surrender, surrender at discretion, cede, capitulate, come to terms, retreat, beat a retreat, draw in one's horns, give way, give round, give in, give up, cave in, suffer judgment by default, bend, bend to one's yoke, bend before the storm, reel back, bend down, knuckle down, knuckle to, knuckle under, knock under, eat dirt, eat the leek, eat humble pie, bite the dust, lick the dust, be at one's feet, fall at one's feet, craven, crouch before, throw oneself at the feet of, swallow the leek, swallow the pill, kiss the rod, turn the other cheek, avaler les couleuvres, gulp down, obey, kneel to, bow to, pay homage to, cringe to, truckle to, bend the neck, bend the knee, kneel, fall on one's knees, bow submission, courtesy, curtsy, kowtow, pocket the affront, make the best of, make a virtue of necessity, grin and abide, grin and bear it, shrug the shoulders, resign oneself, submit with a good grace.