Elfishly is an adverb which means to behave or act in a mischievous, playful or impish way. Synonyms for elfishly includes words like mischievously, impishly, playfully, whimsically, roguishly, puckishly, naughtily, frolicsomely, jokingly, and teasingly. These words generally refer to playful or teasing behavior motivated by a desire to have fun rather than to do harm. Whether one is describing the behavior of a child at play or of a coquettish romantic partner, elfishly can be an effective way to describe the light and playful behavior that is endearing and charming rather than menacing or dangerous.