multiple sclerosis vs MS

multiple sclerosis and MS both are nouns.

Word	Noun	Adjective	Verb	Adverb
multiple sclerosis	Yes	No	No	No
MS	Yes	No	No	No

As nouns, multiple sclerosis and MS are synonyms defined as:

multiple sclerosis and MS: a chronic progressive nervous disorder involving loss of myelin sheath around certain nerve fibers

Other synonyms of multiple sclerosis include disseminated multiple sclerosis, disseminated sclerosis.

multiple sclerosis (noun)	MS (noun)
a chronic progressive nervous disorder involving loss of myelin sheath around certain nerve fibers	a master's degree in science
	a state in the Deep South on the gulf of Mexico; one of the Confederate States during the American Civil War
	a chronic progressive nervous disorder involving loss of myelin sheath around certain nerve fibers