Merriam-Webster Online Dictionary
complain (verb)intransitive verb
1.
to express grief, pain, or discontent - complaining about the weather
2.
to make a formal accusation or charge
Merriam-Webster Online Thesaurus
complain (verb)to express dissatisfaction, pain, or resentment usually tiresomely
SYNONIMS:
beef, bellyache, bitch, bleat, carp, caterwaul, crab, croak, fuss, gripe, grizzle, grouch, grouse, growl, grumble, grump, holler, inveigh, keen, kick, kvetch, maunder, moan, murmur, mutter, nag, repine, scream, squawk, squeal, wail, whimper, whine, whinge, yammer, yawp ( yaup), yowlRELATED WORDS:
object (to), protest, quarrel (with); cavil, quibble; fret, stew, worry; blubber, cry, sob; bemoan, bewail, deplore, lamentNEAR ANTONYMS:
accept, bear, countenance, endure, take, tolerate; applaud, cheer, commend