spun silk vs yarn

spun silk and yarn both are nouns.

Word	Noun	Adjective	Verb	Adverb
spun silk	Yes	No	No	No
yarn	Yes	No	Yes	No

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

spun silk: yarn made from silk waste.
yarn: a fine cord of twisted fibers (of cotton or silk or wool or nylon etc.) used in sewing and weaving

Other hypernyms of spun silk include thread.

spun silk (noun)	yarn (noun)
yarn made from silk waste.	a fine cord of twisted fibers (of cotton or silk or wool or nylon etc.) used in sewing and weaving
	the act of giving an account describing incidents or a course of events

spun silk (verb)	yarn (verb)
	tell or spin a yarn