hold on vs telephone

hold on is not a noun while telephone is a noun.

Word	Noun	Adjective	Verb	Adverb
hold on	No	No	Yes	No
telephone	Yes	No	Yes	No

hold on (noun)	telephone (noun)
	electronic equipment that converts sound into electrical signals that can be transmitted over distances and then converts received signals back into sounds
	transmitting speech at a distance

hold on (verb)	telephone (verb)
be persistent, refuse to stop	get or try to get into communication (with someone) by telephone
stop and wait, as if awaiting further instructions or developments
hold the phone line open
hold firmly
retain possession of