have vs sustain

have is a noun but sustain is not a noun.

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

As verbs, have and sustain are synonyms defined as:

Other synonyms of have include get, suffer.

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

Other hyponyms of have include get, have, suffer, take, horripilate.

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

have (noun)	sustain (noun)
a person who possesses great material wealth

have (verb)	sustain (verb)
cause to be born	undergo (as of injuries and illnesses)
suffer from; be ill with	establish or strengthen as with new evidence or facts
undergo (as of injuries and illnesses)	admit as valid
cause to move; cause to be in a certain position or condition	supply with necessities and support
undergo	provide with nourishment
cause to do; cause to act in a specified manner	be the physical support of; carry the weight of
serve oneself to, or consume regularly	lengthen or extend in duration or space
have sex with; archaic use
organize or be responsible for
go through (mental or physical states or experiences)
have or possess, either in a concrete or an abstract sense
achieve a point or goal
get something; come into possession of
have ownership or possession of
receive willingly something given or offered
have a personal or business relationship with someone
have as a feature
be confronted with