The Collaborative International Dictionary of English v.0.48:

Mel'ee \M[^e]`l['e]e"\ (m[asl]`l[asl]"), n. [F., fr. m[^e]ler to
   mix. See Meddle, Mell, and cf. Mellay.]
   1. A fight in which the combatants are mingled in one
      confused mass; a hand to hand conflict; an affray.
      [1913 Webster]

   2. A cavalry exercise in which two groups of riders try to
      cut paper plumes off the helmets of their opponents, the
      contest continuing until no member of one group retains
      his plume; -- sometimes called Balaklava m[^e]l['e]e.
      [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

melee
    n 1: a noisy riotous fight [syn: melee, scrimmage, battle
         royal]

Moby Thesaurus II by Grady Ward, 1.0:

53 Moby Thesaurus words for "melee":
   ado, bother, brawl, broil, brouhaha, brush, commotion, disturbance,
   dogfight, donnybrook, donnybrook fair, dustup, embroilment, fight,
   foofaraw, fracas, fray, free-for-all, fuss, hash, hassle,
   helter-skelter, hodgepodge, hubbub, jumble,
   knock-down-and-drag-out, medley, melange, mishmash, pastiche,
   pell-mell, pother, potpourri, racket, rampage, riot,
   rough-and-tumble, roughhouse, row, ruckus, ruction, rumpus,
   scramble, scrimmage, shindy, skirmish, stew, stir, to-do, trouble,
   tumult, turmoil, uproar