flying squirrel

Short definition from Wiktionary

Noun

1. 1
   Any of 43 species of squirrel-like rodents, which glide from tree to tree: The tribe Pteromyini within the family Sciuridae, which are true squirrels.
2. 2
   Any of 43 species of squirrel-like rodents, which glide from tree to tree: The family Anomaluridae, which are only distantly related to the squirrels.