1. [n]  gay or light-hearted recreational activity for diversion or amusement; "it was all done in play"; "their frolic in the surf threatened to become ugly"
2. [v]  play boisterously; "The children frolicked in the garden"; "the gamboling lambs in the meadows"; "The toddlers romped in the palyroom"

1. \Frol"ic\ (fr[o^]l"[i^]k), a. [D. vroolijk; akin to G.
   fr["o]lich, fr. froh, OHG. fr[=o], Dan. fro, OS. fr[=a]h, cf.
   Icel. fr[=a]r swift; all perh. akin to Skr. pru to spring
   up.]
   Full of levity; dancing, playing, or frisking about; full of
   pranks; frolicsome; gay; merry.
         The frolic wind that breathes the spring. --Milton.
         The gay, the frolic, and the loud.       --Waller.
   

2. \Frol"ic\, n.
   1. A wild prank; a flight of levity, or of gayety and mirth.
            He would be at his frolic once again. --Roscommon.
   2. A scene of gayety and mirth, as in lively play, or in
      dancing; a merrymaking.
   

3. \Frol"ic\, v. i. [imp. & p. p. {Frolicked}; p. pr. & vb.
   n. {Frolicking}.]
   To play wild pranks; to play tricks of levity, mirth, and
   gayety; to indulge in frolicsome play; to sport.
         Hither, come hither, and frolic and play. --Tennyson.
   

A Prolog system in Common Lisp.