The Oxford Thesaurus An A-Z Dictionary of Synonyms - larkn.

1) frolic, spree, escapade, caper, fling, romp, adventure, revel, jape, game, antic, horseplay, shenanigans, mischief, prank, practical joke: The boys say they took the horse just as a lark. --v. 2) Often, lark about. frolic, caper, romp, revel, play, sport, cavort, gambol, Colloq skylark: We spent a lot of time larking about after our exams.