dormitory vs dorm

dormitory and dorm both are nouns.

Word	Noun	Adjective	Verb	Adverb
dormitory	Yes	No	No	No
dorm	Yes	No	No	No

As nouns, dormitory and dorm are synonyms defined as:

dormitory and dorm: a college or university building containing living quarters for students

Other synonyms of dormitory include hall, residence hall, student residence.

dormitory (noun)	dorm (noun)
a college or university building containing living quarters for students	a college or university building containing living quarters for students
a large sleeping room containing several beds