The Collaborative International Dictionary of English v.0.48:

Complain \Com*plain"\ (k[o^]m*pl[=a]n"), v. i. [imp. & p. p.
   Complained (k[o^]m*pl[=a]nd"); p. pr. & vb. n.
   Complaining.] [F. complaindre, LL. complangere; com- + L.
   plangere to strike, beat, to beat the breast or head as a
   sign of grief, to lament. See Plaint.]
   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! --Milton.
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   2. To make a formal accusation; to make a charge.
      [1913 Webster]

            Now, Master Shallow, you'll complain of me to the
            king?                                 --Shak.

   Syn: To repine; grumble; deplore; bewail; grieve; mourn;
        regret; murmur.
        [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Complain \Com*plain"\, v. t.
   To lament; to bewail. [Obs.]
   [1913 Webster]

         They might the grievance inwardly complain. --Daniel.
   [1913 Webster]

         By chaste Lucrece's soul that late complain'd
         Her wrongs to us.                        --Shak.
   [1913 Webster]

WordNet (r) 3.0 (2006):

complain
    v 1: express complaints, discontent, displeasure, or
         unhappiness; "My mother complains all day"; "She has a lot
         to kick about" [syn: complain, kick, plain, sound
         off, quetch, kvetch] [ant: cheer, cheer up, chirk
         up]
    2: make a formal accusation; bring a formal charge; "The
       plaintiff's lawyer complained that he defendant had
       physically abused his client"