crepe rubber vs gum elastic

crepe rubber and gum elastic both are nouns.

Word	Noun	Adjective	Verb	Adverb
crepe rubber	Yes	No	No	No
gum elastic	Yes	No	No	No

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

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

crepe rubber (noun)	gum elastic (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