tusker vs mammal

tusker and mammal both are nouns.

Word	Noun	Adjective	Verb	Adverb
tusker	Yes	No	No	No
mammal	Yes	No	No	No

As nouns, mammal is a hypernym of tusker; that is, mammal is a word with a broader meaning than tusker:

tusker: any mammal with prominent tusks (especially an elephant or wild boar)
mammal: any warm-blooded vertebrate having the skin more or less covered with hair; young are born alive except for the small subclass of monotremes and nourished with milk

Other hypernyms of tusker include mammalian.

tusker (noun)	mammal (noun)
any mammal with prominent tusks (especially an elephant or wild boar)	any warm-blooded vertebrate having the skin more or less covered with hair; young are born alive except for the small subclass of monotremes and nourished with milk