The Collaborative International Dictionary of English v.0.48:

abrocome \abrocome\ n.
   1. 1 ratlike rodent of the Andes with soft fur and large
      ears.

   Syn: chinchilla rat, rat chinchilla
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

abrocome
    n 1: ratlike rodent with soft fur and large ears of the Andes
         [syn: abrocome, chinchilla rat, rat chinchilla]