telegraph vs telegraphy

telegraph and telegraphy both are nouns.

Word	Noun	Adjective	Verb	Adverb
telegraph	Yes	No	Yes	No
telegraphy	Yes	No	No	No

As nouns, telegraph and telegraphy are synonyms defined as:

telegraph and telegraphy: apparatus used to communicate at a distance over a wire (usually in Morse code)

telegraph (noun)	telegraphy (noun)
apparatus used to communicate at a distance over a wire (usually in Morse code)	apparatus used to communicate at a distance over a wire (usually in Morse code)
	communicating at a distance by electric transmission over wire

telegraph (verb)	telegraphy (verb)
send cables, wires, or telegrams