Electr. [f. Gr. σύν SYN- + τόνος TONE + -IC.] Denoting a system of wireless telegraphy in which the transmitling and receiving instruments are accurately tuned or adjusted so that the latter responds only to vibrations of the frequency of those emitted by the former; also said of the instruments so tuned.
1892. Lodge, Mod. Views Electr., xvi. 339. The synchronizing of the vibration-period of two things is well expressed by the adjective syntonic which was suggested to me by the late Dr. A. T. Myers. That which has been styled resonance I propose, therefore, to call syntony.
1898. S. P. Thompson, in Jrnl. Soc. Arts, XLVI. 457/1. Using not merely circuits of wires, but syntonic circuits, which are necessarily much more sensitive in their response one to the other.
1898. Echo, 10 Jan., 2/4. These electrical resonances constitute syntonic telegraphy.
Hence Syntonically adv.
In recent Dicts.