insole vs innersole

insole and innersole both are nouns.

Word	Noun	Adjective	Verb	Adverb
insole	Yes	No	No	No
innersole	Yes	No	No	No

As nouns, insole and innersole are synonyms defined as:

insole and innersole: the inner sole of a shoe or boot where the foot rests

insole (noun)	innersole (noun)
the inner sole of a shoe or boot where the foot rests	the inner sole of a shoe or boot where the foot rests