Source : Webster's Revised Unabridged Dictionary (1913)

Prankish \Prank"ish\, a.
   Full of pranks; frolicsome.

Source : WordNet®

prankish
     adj : naughtily or annoyingly playful; "teasing and worrying with
           impish laughter" [syn: {impish}, {implike}, {mischievous},
            {pixilated}, {puckish}]