lagging vs insulant

lagging and insulant both are nouns.

Word	Noun	Adjective	Verb	Adverb
lagging	Yes	No	No	No
insulant	Yes	No	No	No

As nouns, insulant is a hypernym of lagging; that is, insulant is a word with a broader meaning than lagging:

lagging: insulation used to wrap around pipes or boilers or laid in attics to prevent loss of heat
insulant: insulating material that reduces or prevents the transmission of heat or sound or electricity

Other hypernyms of lagging include insulation.

lagging (noun)	insulant (noun)
insulation used to wrap around pipes or boilers or laid in attics to prevent loss of heat	insulating material that reduces or prevents the transmission of heat or sound or electricity