Mustela rixosa vs weasel

Mustela rixosa and weasel both are nouns.

Word	Noun	Adjective	Verb	Adverb
Mustela rixosa	Yes	No	No	No
weasel	Yes	No	No	No

As nouns, weasel is a hypernym of Mustela rixosa; that is, weasel is a word with a broader meaning than Mustela rixosa:

Mustela rixosa: of Canada and northeastern United States
weasel: small carnivorous mammal with short legs and elongated body and neck

Mustela rixosa (noun)	weasel (noun)
of Canada and northeastern United States	small carnivorous mammal with short legs and elongated body and neck
	a person who is regarded as treacherous or sneaky