Definition of "ermine"

A weasel found in northern latitudes (Mustela erminea in Eurasia, Alaska, and the Arctic, Mustela haidarum in Haida Gwaii, Mustela richardsonii in the rest of North America); its dark brown fur turns white in winter, apart from the black tip of the tail.  examples

The white fur of this animal, traditionally seen as a symbol of purity and used for judges' robes.  examples

(by extension, figuratively) The office of a judge.  examples

(heraldry) A white field with black spots.  examples

Any of various moths, especially in the family Yponomeutidae  examples

(heraldry) In blazon, of the colour ermine (white with black spots).  examples

To clothe with ermine.  examples