ferret Look up ferret at Dictionary.com
late 14c., from O.Fr. fuiret, dim. of fuiron "weasel, ferret," lit. "thief," from L.L. furionem (related to furonem "cat," and also "robber"), probably from L. fur (gen. furis) "thief." The verb (mid-15c.) refers to the use of half-tame ferrets to kill rats and flush rabbits from burrows; the extended sense of "search out, discover" is 1570s.