malaprop vs malapropism

malaprop and malapropism both are nouns.

Word	Noun	Adjective	Verb	Adverb
malaprop	Yes	No	No	No
malapropism	Yes	No	No	No

As nouns, malaprop and malapropism are synonyms defined as:

malaprop and malapropism: the unintentional misuse of a word by confusion with one that sounds similar

malaprop (noun)	malapropism (noun)
the unintentional misuse of a word by confusion with one that sounds similar	the unintentional misuse of a word by confusion with one that sounds similar