telegram vs cable

telegram and cable both are nouns.

Word	Noun	Adjective	Verb	Adverb
telegram	Yes	No	No	No
cable	Yes	No	Yes	No

As nouns, cable is a hyponym of telegram; that is, cable is a word with a more specific, narrower meaning than telegram:

Other hyponyms of telegram include cablegram, overseas telegram, letter telegram, night letter.

telegram (noun)	cable (noun)
a message transmitted by telegraph	a very strong thick rope made of twisted hemp or steel wire
	a television system that transmits over cables
	a conductor for transmitting electrical or optical signals or electric power
	a telegram sent abroad
	television that is transmitted over cable directly to the receiver
	a nautical unit of depth

telegram (verb)	cable (verb)
	send cables, wires, or telegrams
	fasten with a cable