[f. TONE v. + -ER1.] One who or that which tones: see the verb.
1888. Medical News, LIII. 499. Sulphuric and nitric acids have … some claim to be regarded as toners of the vasomotor nerves.
1904. Daily Chron., 25 March, 10/7. Pianos.—Experienced tuner and toner wanted in factory.
