Mooning

Moon \Moon\, v. t. [imp. & p. p. {Mooned}; p. pr. & vb. n.
   {Mooning}.]
   1. To expose to the rays of the moon.
      [1913 Webster]

            If they have it to be exceeding white indeed, they
            seethe it yet once more, after it hath been thus
            sunned and mooned.                    --Holland.
      [1913 Webster]

   2. To expose one's naked buttocks to (a person); -- a vulgar
      sign of contempt or disrespect, sometimes done as a prank.
      [PJC]
    

62 Moby Thesaurus words for "mooning":
      Walter Mitty, absence of mind, absent, absentminded,
      absentmindedness, absorbed, absorption, abstracted, abstractedness,
      abstraction, bemused, bemusement, brown study, castle-building,
      daydream, daydreamer, daydreaming, daydreamy, depth of thought,
      dream, dreaming, dreamy, drowsing, ecstatic, elsewhere, engrossed,
      engrossment, fantasy, fantasying, faraway, fit of abstraction,
      half-awake, in a reverie, in the clouds, lost, lost in thought,
      meditative, moonraking, muse, museful, musefulness, musing,
      muted ecstasy, napping, nodding, oblivious, pensive, pipe dream,
      pipe-dreaming, preoccupation, preoccupied, rapt, reverie,
      somewhere else, stargazing, study, taken up, trance, transported,
      unconscious, woolgathering, wrapped in thought