stretchiness vs elasticity

stretchiness and elasticity both are nouns.

Word	Noun	Adjective	Verb	Adverb
stretchiness	Yes	No	No	No
elasticity	Yes	No	No	No

As nouns, elasticity is a hypernym of stretchiness; that is, elasticity is a word with a broader meaning than stretchiness:

stretchiness: the capacity for being stretched
elasticity: the tendency of a body to return to its original shape after it has been stretched or compressed

Other hypernyms of stretchiness include snap.

stretchiness (noun)	elasticity (noun)
the capacity for being stretched	the tendency of a body to return to its original shape after it has been stretched or compressed