silk vs animal fibre

silk and animal fibre both are nouns.

Word	Noun	Adjective	Verb	Adverb
silk	Yes	No	No	No
animal fibre	Yes	No	No	No

As nouns, animal fibre is a hypernym of silk; that is, animal fibre is a word with a broader meaning than silk:

silk: animal fibers produced by silkworms and other larvae that spin cocoons and by most spiders
animal fibre: fiber derived from animals

Other hypernyms of silk include animal fiber.

silk (noun)	animal fibre (noun)
a fabric made from the fine threads produced by certain insect larvae	fiber derived from animals
animal fibers produced by silkworms and other larvae that spin cocoons and by most spiders