The Collaborative International Dictionary of English v.0.48:

Swiftlet \Swift"let\, n. (Zool.)
   Any one of numerous species of small East Indian and Asiatic
   swifts of the genus Collocalia. Some of the species are
   noted for furnishing the edible bird's nest. See Illust.
   under Edible.
   [1913 Webster]

WordNet (r) 3.0 (2006):

swiftlet
    n 1: swift of eastern Asia; produces the edible bird's nest
         [syn: swiftlet, Collocalia inexpectata]