from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Of, relating to, or being a telephone with which the user places calls by pressing pushbuttons that generate and transmit tones of differing pitch, these tones corresponding to the digits of the number being called.
- n. A touch-tone telephone.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Relating to a type of telephone with buttons, each of which produces a tone which corresponds to the relevant digit.
From the trade name Touch-Tone, 1960. (Wiktionary)