Any of an order (Rodentia) of relatively small gnawing mammals (as a mouse, a squirrel, or a beaver) that have in both jaws a single pair of teeth with a chisel-shaped edge.
The gnawing Mammalia, such as the Rats, Rabbits, and Squirrels. They are especially characterised by the possession of a single pair of chisel-like cutting teeth in each jaw, between which and the grinding teeth there is a great gap. 185
organisms belonging to an order of herbivorous or scavenging mammals in which the incisors are reduced to one pair in each jaw and have enamel that grows continually S to Z