The Collaborative International Dictionary of English v.0.48:

Serape \Se*ra"pe\, n. [Sp. Amer. sarape.]
   A blanket or shawl worn as an outer garment by the Spanish
   Americans, as in Mexico.
   [1913 Webster]

WordNet (r) 3.0 (2006):

serape
    n 1: a long brightly colored shawl; worn mainly by Mexican men
         [syn: serape, sarape]