| Noun | 1. | New World mouse - a variety of rodent 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 American harvest mouse, harvest mouse - any of several small greyish New World mice inhabiting e.g. grain fields |