Source : Webster's Revised Unabridged Dictionary (1913)

Boisterous \Bois"ter*ous\, a. [OE. boistous; of uncertain
   origin; cf. W. bwyst wild, savage, wildness, ferocity,
   bwystus ferocious.]
   1. Rough or rude; unbending; unyielding; strong; powerful.
      [Obs.] ``Boisterous sword.'' ``Boisterous hand.'' --Shak.

   2. Exhibiting tumultuous violence and fury; acting with noisy
      turbulence; violent; rough; stormy.

            The waters swell before a boisterous storm. --Shak.

            The brute and boisterous force of violent men.
                                                  --Milton.

   3. Noisy; rough; turbulent; as, boisterous mirth; boisterous
      behavior.

            I like not that loud, boisterous man. --Addison.

   4. Vehement; excessive. [R.]

            The heat becomes too powerful and boisterous for
            them.                                 --Woodward.

   Syn: Loud; roaring; violent; stormy; turbulent; furious;
        tumultuous; noisy; impetuous; vehement.

Source : WordNet®

boisterous
     adj 1: noisy and lacking in restraint or discipline; "a boisterous
            crowd"; "a social gathering that became rambunctious
            and out of hand"; "a robustious group of teenagers";
            "beneath the rumbustious surface of his paintings is
            sympathy for the vulnerability of ordinary human
            beings"; "an unruly class" [syn: {rambunctious}, {robustious},
             {rumbustious}, {unruly}]
     2: full of rough and exuberant animal spirits; "boisterous
        practical jokes"; "knockabout comedy" [syn: {knockabout}]
     3: violently agitated and turbulent; "boisterous winds and
        waves"; "the fierce thunders roar me their music"- Ezra
        Pound; "rough weather"; "rough seas" [syn: {fierce}, {rough}]