telegraph line vs telephone line

telegraph line and telephone line both are nouns.

Word	Noun	Adjective	Verb	Adverb
telegraph line	Yes	No	No	No
telephone line	Yes	No	No	No

As nouns, telegraph line and telephone line are synonyms defined as:

telegraph line and telephone line: the wire that carries telegraph and telephone signals

Other synonyms of telegraph line include telegraph wire, telephone wire.

telegraph line (noun)	telephone line (noun)
the wire that carries telegraph and telephone signals	a telephone connection
	the wire that carries telegraph and telephone signals