The Collaborative International Dictionary of English v.0.48:

Telegraphy \Te*leg"ra*phy\, n. [Cf. F. t['e]l['e]graphie.]
   The science or art of constructing, or of communicating by
   means of, telegraphs; as, submarine telegraphy.
   [1913 Webster]

WordNet (r) 3.0 (2006):

telegraphy
    n 1: communicating at a distance by electric transmission over
         wire
    2: apparatus used to communicate at a distance over a wire
       (usually in Morse code) [syn: telegraph, telegraphy]

Moby Thesaurus II by Grady Ward, 1.0:

32 Moby Thesaurus words for "telegraphy":
   TelAutography, Teletype, Teletype network, Teletyping,
   closed-circuit telegraphy, code, duplex telegraphy, electricity,
   facsimile telegraph, interrupter, key, multiplex telegraphy,
   news ticker, quadruplex telegraphy, railroad telegraphy, receiver,
   sender, simplex telegraphy, single-current telegraphy, sounder,
   stock ticker, submarine telegraphy, telegraphics, teleprinter,
   teletypewriter, teletypewriting, telex, ticker, transmitter,
   typotelegraph, typotelegraphy, wire service



The Free On-line Dictionary of Computing (30 December 2018):

telegraphy

    A historical term for communication,
   either wired or wireless, using Morse code.  The term is
   used in contrast with telephony meaning voice transmission.
   Telegraphy is sometimes (somewhat incorrectly) referred to as
   "continuous wave" or CW transmission.

   (2009-11-24)