foam rubber vs India rubber

foam rubber and India rubber both are nouns.

Word	Noun	Adjective	Verb	Adverb
foam rubber	Yes	No	No	No
India rubber	Yes	No	No	No

As nouns, India rubber is a hypernym of foam rubber; that is, India rubber is a word with a broader meaning than foam rubber:

foam rubber: spongy rubber; made by introducing air bubbles before vulcanization and used for cushioning or upholstery
India rubber: an elastic material obtained from the latex sap of trees (especially trees of the genera Hevea and Ficus) that can be vulcanized and finished into a variety of products

Other hypernyms of foam rubber include foam, caoutchouc, gum elastic, natural rubber, rubber.

foam rubber (noun)	India rubber (noun)
spongy rubber; made by introducing air bubbles before vulcanization and used for cushioning or upholstery	an elastic material obtained from the latex sap of trees (especially trees of the genera Hevea and Ficus) that can be vulcanized and finished into a variety of products