dialyoudaoicibaDictYouDict[dial 词源字典]
dial: [15] The original application of the word dial in English is ‘sundial’. The evidence for its prehistory is patchy, but it is generally presumed to have come from medieval Latin diālis ‘daily’, a derivative of Latin diēs ‘day’, the underlying notion being that it records the passage of a 24- hour period.
[dial etymology, dial origin, 英语词源]
dial (n.)youdaoicibaDictYouDict
early 15c., "sundial," earlier "dial of a compass" (mid-14c.), apparently from Medieval Latin dialis "daily," from Latin dies "day" (see diurnal).

The word perhaps was abstracted from a phrase such as Medieval Latin rota dialis "daily wheel," and evolved to mean any round plate over which something rotates. Telephone sense is from 1879, which led to dial tone (1921), "the signal to begin dialing," which term soon might be the sole relic of the rotary phone.
dial (v.)youdaoicibaDictYouDict
1650s, "to work with aid of a dial or compass," from dial (n.). Telephone sense is from 1923. Related: Dialed; dialing.