The Collaborative International Dictionary of English v.0.48:

Tussah \Tus"sah\ Tusseh \Tus"seh\(t[u^]s"s[.a]), n. [Also
   tussa, tussar, tusser, tussur, etc.] [Prob. fr. Hind.
   tasar a shuttle, Skr. tasara, trasara.]
   An undomesticated East Indian silkworn (Antheraea mylitta),
   that feeds on the leaves of the oak and other plants.
   [Webster 1913 Suppl.]