Noun | 1. | ![]() mammal genus - a genus of mammals family Muridae, Muridae - originally Old World rats now distributed worldwide; distinguished from the Cricetidae by typically lacking cheek pouches fieldmouse, field mouse - any nocturnal Old World mouse of the genus Apodemus inhabiting woods and fields and gardens Apodemus sylvaticus, European wood mouse - nocturnal yellowish-brown mouse inhabiting woods and fields and gardens |