The Collaborative International Dictionary of English v.0.48:
Whahoo \Wha*hoo"\, n. (Bot.) An American tree, the winged elm. (Ulmus alata). [1913 Webster]WordNet (r) 3.0 (2006):
Ulmus alata n 1: North American elm having twigs and young branches with prominent corky projections [syn: winged elm, wing elm, Ulmus alata]