MS vs master's degree

MS and master's degree both are nouns.

Word	Noun	Adjective	Verb	Adverb
MS	Yes	No	No	No
master's degree	Yes	No	No	No

As nouns, master's degree is a hypernym of MS; that is, master's degree is a word with a broader meaning than MS:

MS: a master's degree in science
master's degree: an academic degree higher than a bachelor's degree but lower than a doctor's degree

MS (noun)	master's degree (noun)
a master's degree in science	an academic degree higher than a bachelor's degree but lower than a doctor's degree
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