glass wool vs insulator

glass wool and insulator both are nouns.

Word	Noun	Adjective	Verb	Adverb
glass wool	Yes	No	No	No
insulator	Yes	No	No	No

As nouns, insulator is a hypernym of glass wool; that is, insulator is a word with a broader meaning than glass wool:

glass wool: glass fibers spun and massed into bundles resembling wool
insulator: a material such as glass or porcelain with negligible electrical or thermal conductivity

Other hypernyms of glass wool include filter, dielectric, nonconductor.

glass wool (noun)	insulator (noun)
glass fibers spun and massed into bundles resembling wool	a material such as glass or porcelain with negligible electrical or thermal conductivity