intercom vs door phone

intercom and door phone both are nouns.

Word	Noun	Adjective	Verb	Adverb
intercom	Yes	No	No	No
door phone	Yes	No	No	No

As nouns, door phone is a hyponym of intercom; that is, door phone is a word with a more specific, narrower meaning than intercom:

intercom: a communication system linking different rooms within a building or ship etc
door phone: a set of electrical and electronic elements used to handle two-way communication (street to home) in houses, apartments or villas.

Other hyponyms of intercom include interphone, door bell phone.

intercom (noun)	door phone (noun)
a communication system linking different rooms within a building or ship etc	a set of electrical and electronic elements used to handle two-way communication (street to home) in houses, apartments or villas.