ermineyoudaoicibaDictYouDict[ermine 词源字典]
ermine: [12] The term ermine was introduced to English from Old French as a name for the ‘stoat’, but as in the case of other words of French origin like mutton and pork which soon came to be used for the dead animals’ product rather than the live animals themselves, it was not long (about a hundred years in fact) before ermine was being applied to the stoat’s fur, and specifically to its white winter fur.

The source of the French word is not entirely clear. One school of thought derives it from medieval Latin mūs Armenius ‘Armenian mouse’, on the assumption that this denoted a ‘stoat’ or ‘weasel’, but an alternative possibility is Germanic origin.
[ermine etymology, ermine origin, 英语词源]
ermine (n.)youdaoicibaDictYouDict
late 12c., from Old French ermine (12c., Modern French hermine), used in reference to both the animal and the fur. Apparently the word is a convergence of Latin (mus) Armenius "Armenian (mouse)" -- ermines being abundant in Asia Minor -- and an unrelated Germanic word for "weasel" (represented by Old High German harmo "ermine, stoat, weasel," adj. harmin; Old Saxon harmo, Old English hearma "shrew," etc.) that happened to sound like it. OED splits the difference between competing theories. The fur, especially with the black of the tail inserted at regular intervals in the pure white of the winter coat, was used for the lining of official and ceremonial garments, in England especially judicial robes, hence figurative use from 18c. for "the judiciary." Related: Ermined.