(1):

(v. i.) Any one of numerous species of small rodents belonging to the genus Sciurus and several allied genera of the family Sciuridae. Squirrels generally have a bushy tail, large erect ears, and strong hind legs. They are commonly arboreal in their habits, but many species live in burrows.

(2):

(v. i.) One of the small rollers of a carding machine which work with the large cylinder.