crepe rubber vs caoutchouc

crepe rubber and caoutchouc both are nouns.

Word	Noun	Adjective	Verb	Adverb
crepe rubber	Yes	No	No	No
caoutchouc	Yes	No	No	No

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

crepe rubber: crude natural rubber; used mainly for shoe soles
caoutchouc: 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 crepe rubber include gum elastic, India rubber, natural rubber, rubber.

crepe rubber (noun)	caoutchouc (noun)
crude natural rubber; used mainly for shoe soles	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