Synonyms to as a joke

in fun, devilishly, elfishly, for amusement, for fun, for kicks, for laughs, for sport, impishly, in jest, in joke, in play, in sport, jestingly, jokingly, knavishly, mischievously, playfully, prankishly, puckishly, roguishly, scampishly, sportively, waggishly