Merriam-Webster's Collegiate® Dictionary, 11th Edition
SQUIRREL
I. noun (plural squirrels; also squirrel) see: shine
Date: 14th century
any of various small or medium-sized rodents (family Sciuridae, the squirrel family): as, any of numerous New or Old World arboreal forms having a long bushy tail and strong hind legs, ground squirrel , the fur of a squirrel,
II. transitive verb (-reled or -relled; -reling or -relling)
Etymology: from the squirrel's habit of storing up gathered nuts and seeds for winter use
Date: 1925
to store up for future use