wireless telegraph vs wireless telegraphy

wireless telegraph and wireless telegraphy both are nouns.

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

As nouns, wireless telegraph and wireless telegraphy are synonyms defined as:

wireless telegraph and wireless telegraphy: the use of radio to send telegraphic messages (usually by Morse code)

Other synonyms of wireless telegraph include radiotelegraph, radiotelegraphy.

wireless telegraph (noun)	wireless telegraphy (noun)
the use of radio to send telegraphic messages (usually by Morse code)	the use of radio to send telegraphic messages (usually by Morse code)
	telegraphy that uses transmission by radio rather than by wire