(skwÃ»râ²Él, skwÅ­râ²-) n. 1. Any of various arboreal rodents of the tribe Sciurini and especially of the genus Sciurus, characteristically having a long flexible bushy tail. Also called tree squirrel. 2. Any of various other rodents of the family Sciuridae, such as the ground squirrels and the flying squirrels.