Source : Webster's Revised Unabridged Dictionary (1913)

Syntony \Syn"to*ny\, n. [Cf. Gr. ? agreement. See {Syn-};
   {Tone}.] (Physics)
   State of being adjusted to a certain wave length; agreement
   or tuning between the time period of an apparatus emitting
   electric oscillations and that of a receiving apparatus, esp.
   in wireless telegraphy.