noun
: a bulky fossorial nocturnal rodent ( Aplodontia rufa ) of the uplands of the Pacific coast of No. America having small ears and eyes and a rudimentary tail and superficially resembling the ground squirrels to which it is actually but distantly related being the sole recent survivor of a once extensive group (Aplodontoidea of the Sciuromorpha), of primitive rodents that first appeared in the Paleocene