The word "hyrmine" is derived from the Old French word "hermin", which originally referred to the white winter fur of the stoat (a small carnivorous mammal). The Old French term ultimately comes from the Latin word "ermīnus", which also referred to the stoat. Over time, "hermin" transformed into "hermine" in Middle French before entering the English language. The term "hyrmine" is still used to describe the stoat or its fur today, particularly in heraldry.