From WordNet (r) 3.0 (2006) [wn]:
handstand
n 1: the act of supporting yourself by your hands alone in an
upside down position
From The Collaborative International Dictionary of English v.0.48 [gcide]:
handstand \handstand\ n.
The gymnastic act of supporting oneself by one's hands alone
in an upside down position; as, to do handstands for
exercise.
[WordNet 1.5 +PJC]