The Collaborative International Dictionary of English v.0.48:

Clumber \Clum"ber\ (kl[u^]m"b[~e]r), n. [Named from the estate
   of the Duke of Newcastle.] (Zool.)
   A kind of field spaniel, with short legs and stout body,
   which, unlike other spaniels, hunts silently.
   [1913 Webster]

WordNet (r) 3.0 (2006):

clumber
    n 1: a thickset spaniel with longish silky hair [syn: clumber,
         clumber spaniel]