The Collaborative International Dictionary of English v.0.48:
Upend \Up*end"\, v. t. To end up; to set on end, as a cask. [1913 Webster]WordNet (r) 3.0 (2006):
upend v 1: become turned or set on end; "the airplanes upended" 2: set, turn, or stand on end; "upend the box and empty the contents"