knuckle under

1 to cease resistance (as to another's arguments, demands, or control) <encouraged her to stand firm and not knuckle under to political pressure> Synonyms blink, bow, budge, capitulate, concede, give in, yield, quit, relent, submit, succumb, surrenderRelated Words acquiesce; deferNear Antonyms contend, fight, hold off; battle, breast, combat, confront, counter, defy, face, meet, object, oppose, repel; thwart, withstandAntonyms resist

2 to yield to the control or power of enemy forces <the remote outpost was overrun and forced to knuckle under> Synonyms capitulate, give up, fall, submit, succumb, surrenderRelated Words bow, buckle, cave (in), collapse, give (in); hand over, relinquish; lose; concede, fail, foldNear Antonyms buck, defy, fight, oppose, repel, resist, withstand; beat, overcome, win; conquer, prevail, triumphAntonyms endure, stand