Noun | 1. | ![]() gnawer, rodent - relatively small placental mammals having a single pair of constantly growing incisor teeth specialized for gnawing Cricetidae, family Cricetidae - mostly small New World rodents including New World mice and lemmings and voles and hamsters European lemming, Lemmus lemmus - notable for mass migrations even into the sea where many drown brown lemming, Lemmus trimucronatus - of northwestern Canada and Alaska pied lemming - North American lemming having a white winter coat and some claws much enlarged southern bog lemming, Synaptomys cooperi - of low bogs and meadows of northeastern and central United States and southern Canada northern bog lemming, Synaptomys borealis - of wet alpine and subalpine meadows of Canada and Alaska |