THESAURUS
knuckle down
accede, accept, acquiesce, assent, be agreeable, buckle down, comply, consent, endeavor, face the music, go all out, go along with, hump, hump it, knock under, knuckle under, lay to, live with it, not resist, obey, ply the oar, relent, resign, spare no effort, submit, succumb, swallow it, swallow the pill, take, take it
ROGET THESAURUS
knuckle down
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.