The definition of a weasel is an animal in the genus Mustela that's thin, has a long tail and eats small animals, or a sneaky person.(noun)
See weasel in Webster's New World College Dictionary
Origin: ME wesel < OE wesle, akin to Ger wiesel, prob. < IE base *weis-, to flow out (with reference to the rank odor emitted by the animal) > virus, bison
See weasel in American Heritage Dictionary 4
Origin: Middle English wesele
Origin: , from Old English wesle.
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