1.  complain(v = verb.communication) kick, kvetch, plain, quetch, sound off - express complaints, discontent, displeasure, or unhappiness; "My mother complains all day"; "She has a lot to kick about"
Antonym: cheer
Derived forms noun complainer₁, noun complaint₃
Sample sentences: They complain that there was a traffic accident

2.  complain(v = verb.communication) - make a formal accusation; bring a formal charge; "The plaintiff's lawyer complained that he defendant had physically abused his client"
is one way to charge
Derived forms noun complainant₁, noun complaint₅, noun complaint₄
Sample sentences: Somebody ----s that CLAUSE

1.  To give utterance to expression of grief, pain, censure, regret. etc.; to lament; to murmur; to find fault; -- commonly used with of. Also, to creak or squeak, as a timber or wheel. [1913 Webster]
"O loss of sight, of thee I most complain!" [1913 Webster]

2.  To make a formal accusation; to make a charge. [1913 Webster]
"Now, Master Shallow, you'll complain of me to the king?"

   To lament; to bewail. [1913 Webster]
"They might the grievance inwardly complain." [1913 Webster]
"By chaste Lucrece's soul that late complain'd
Her wrongs to us." [1913 Webster]

complain, v.intr.
1 (often foll. by about, at, or that + clause) express dissatisfaction (complained at the state of the room; is always complaining).
2 (foll. by of) a announce that one is suffering from (an ailment) (complained of a headache). b state a grievance concerning (complained of the delay).
3 make a mournful sound; groan, creak under a strain.

Derivative:
complainer n. complainingly adv.

Etymology:
ME f. OF complaindre (stem complaign-) f. med.L complangere bewail (as COM-, plangere planct- lament)

VB  lament, mourn, deplore, grieve, weep over, bewail, bemoan, condole with, fret, wear mourning, go into mourning, put on mourning, wear the willow, wear sackcloth and ashes, infandum renovare dolorem, give sorrow words, sigh, give a sigh, heave, fetch a sigh, waft a sigh from Indus to the pole, sigh 'like a furnace', wail, cry, weep, sob, greet, blubber, pipe, snivel, bibber, whimper, pule, pipe one's eye, drop tears, shed tears, drop a tear, shed a tear, melt into tears, burst into tears, fondre en larmes, cry oneself blind, cry one's eyes out, yammer, scream, mew, groan, moan, whine, roar, roar like a bull, bellow like a bull, cry out lustily, rend the air, frown, scowl, make a wry face, gnash one's teeth, wring one's hands, tear one's hair, beat one's breast, roll on the ground, burst with grief, complain, murmur, mutter, grumble, growl, clamor, make a fuss about, croak, grunt, maunder, deprecate, cry out before one is hurt, complain without cause.