Source : Webster's Revised Unabridged Dictionary (1913)

Frivol \Friv"ol\, v. i.
   To act frivolously; to trifle. --Kipling. -- {Friv"ol*er},
   {Friv"ol*ler}, n. [All Colloq.]

Source : WordNet®

frivol
     v : act frivolously [syn: {trifle}]
     [also: {frivolling}, {frivolled}]