- dial
- 1430, apparently from M.L. dialis "daily," from L. dies "day" (see diurnal). The M.L. was probably abstracted from a phrase such as rota dialis "daily wheel," and the earliest sense was "a sundial." It evolved to mean any round plate over which something rotates, including the telephone sense, from 1879, which led to the verb (1923) and to dial tone (1921), "the signal to begin dialing," which term soon will be the sole relic of the rotary phone.