n. (informal)
25B6; noun
we were just having a bit of a lark : FUN, amusement, laugh, giggle, joke; escapade, prank, trick, jape, practical joke; informal leg-pull; ( larks ) antics, high jinks, horseplay, mischief, tomfoolery; informal shenanigans, monkey business; Brit. informal monkey tricks; dated sport.
I've got this snowboarding lark sussed : ACTIVITY; hobby, pastime, task; informal business, caper.
25B6; verb he's always larking about : FOOL ABOUT/AROUND, play tricks, make mischief, monkey about/around, clown about/around, have fun, skylark; informal mess about/around; Brit. informal muck about/around.