ermine vs least weasel

ermine

noun
  • 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. 

  • A white field with black spots. 

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

  • Any of various moths, especially in the family Yponomeutidae 

  • The office of a judge. 

adj
  • In blazon, of the colour ermine (white with black spots). 

verb
  • To clothe with ermine. 

least weasel

noun
  • The common weasel, little weasel, or simply weasel (Mustela nivalis), the smallest member of the weasel genus Mustela, native to Eurasia, North America, and North Africa. 

How often have the words ermine and least weasel occurred in a corpus of books? (source: Google Ngram Viewer )