The Collaborative International Dictionary of English v.0.48:

Cassowary \Cas"so*wa*ry\, n.; pl. Cassowaries. [Malay
   kasu[=a]ri.] (Zool.)
   A large bird, of the genus Casuarius, found in the east
   Indies. It is smaller and stouter than the ostrich. Its head
   is armed with a kind of helmet of horny substance, consisting
   of plates overlapping each other, and it has a group of long
   sharp spines on each wing which are used as defensive organs.
   It is a shy bird, and runs with great rapidity. Other species
   inhabit New Guinea, Australia, etc.
   [1913 Webster] Cassumunar

WordNet (r) 3.0 (2006):

cassowary
    n 1: large black flightless bird of Australia and New Guinea
         having a horny head crest