The Collaborative International Dictionary of English v.0.48:

Stupeous \Stu"pe*ous\, a. [L. stupa, or better stuppa, tow; cf.
   L. stuppeus made of tow. Cf. Stupose.]
   Resembling tow; having long, loose scales, or matted
   filaments, like tow; stupose.
   [1913 Webster]