weekend warrior vs reservist

weekend warrior and reservist both are nouns.

Word	Noun	Adjective	Verb	Adverb
weekend warrior	Yes	No	No	No
reservist	Yes	No	No	No

As nouns, reservist is a hypernym of weekend warrior; that is, reservist is a word with a broader meaning than weekend warrior:

weekend warrior: a reservist who fulfills the military obligation on weekends
reservist: a member of a military reserve

weekend warrior (noun)	reservist (noun)
a reservist who fulfills the military obligation on weekends	a member of a military reserve
a homeowner who acts as a contractor and tries to do major improvement projects on weekends (often without understanding the scope of the work to be done)