noun
An often domesticated mammal (Mustela putorius furo) rather like a weasel, descended from the polecat and often trained to hunt burrowing animals.
A black-footed ferret (Mustela nigripes).
(figurative) A diligent searcher.
verb
To hunt game with ferrets.
(by extension, ambitransitive) To uncover and bring to light by searching; usually to ferret out.
noun
(dated) A tape of silk, cotton, or ribbon, used to tie documents, clothing, etc. or along the edge of fabric.