sustain vs cramp

sustain is not a noun while cramp is a noun.

Word	Noun	Adjective	Verb	Adverb
sustain	No	No	Yes	No
cramp	Yes	No	Yes	No

As verbs, cramp is a hyponym of sustain; that is, cramp is a word with a more specific, narrower meaning than sustain:

Other hyponyms of sustain include break down, collapse, break up, collapse, crack, crack up, crock up, stress.

sustain (noun)	cramp (noun)
	a strip of metal with ends bent at right angles; used to hold masonry together
	a clamp for holding pieces of wood together while they are glued
	a painful and involuntary muscular contraction

sustain (verb)	cramp (verb)
undergo (as of injuries and illnesses)	suffer from sudden painful contraction of a muscle
establish or strengthen as with new evidence or facts	affect with or as if with a cramp
admit as valid	prevent the progress or free movement of
supply with necessities and support	secure with a cramp
provide with nourishment
be the physical support of; carry the weight of
lengthen or extend in duration or space