The Collaborative International Dictionary of English v.0.48:

Prank \Prank\, v. t. [imp. & p. p. Pranked; p. pr. & vb. n.
   Pranking.] [Cf. E. prink, also G. prangen, prunken, to
   shine, to make a show, Dan. prange, prunke, Sw. prunka, D.
   pronken.]
   To adorn in a showy manner; to dress or equip ostentatiously;
   -- often followed by up; as, to prank up the body. See
   Prink.
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         In sumptuous tire she joyed herself to prank.
                                                  --Spenser.
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The Collaborative International Dictionary of English v.0.48:

Prank \Prank\, v. i.
   To make ostentatious show.
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         White houses prank where once were huts. --M. Arnold.
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The Collaborative International Dictionary of English v.0.48:

Prank \Prank\, n.
   A gay or sportive action; a ludicrous, merry, or mischievous
   trick; a caper; a frolic. --Spenser.
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         The harpies . . . played their accustomed pranks. --Sir
                                                  W. Raleigh.
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         His pranks have been too broad to bear with. --Shak.
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The Collaborative International Dictionary of English v.0.48:

Prank \Prank\, a.
   Full of gambols or tricks. [Obs.]
   [1913 Webster]

WordNet (r) 3.0 (2006):

prank
    n 1: acting like a clown or buffoon [syn: buffoonery,
         clowning, japery, frivolity, harlequinade, prank]
    2: a ludicrous or grotesque act done for fun and amusement [syn:
       antic, joke, prank, trick, caper, put-on]
    v 1: dress or decorate showily or gaudily; "Roses were pranking
         the lawn"
    2: dress up showily; "He pranked himself out in his best
       clothes"