MEDLINE vs phone system

MEDLINE and phone system both are nouns.

Word	Noun	Adjective	Verb	Adverb
MEDLINE	Yes	No	No	No
phone system	Yes	No	No	No

As nouns, phone system is a hypernym of MEDLINE; that is, phone system is a word with a broader meaning than MEDLINE:

MEDLINE: the computer-based telephone system of the United States National Library of Medicine that provides rapid linkage to MEDLARS
phone system: a communication system that transmits sound between distant points

Other hypernyms of MEDLINE include telephone system.

MEDLINE (noun)	phone system (noun)
the computer-based telephone system of the United States National Library of Medicine that provides rapid linkage to MEDLARS	a communication system that transmits sound between distant points