di·al / ˈdī(ə)l/ • n. a face of a clock, watch, or sundial that is marked to show units of time. ∎  a similar face or flat plate with a scale and pointer for showing measurements of weight, volume, pressure, compass direction, etc. ∎  a disk with numbered holes on a telephone, enabling someone to make a call by inserting a finger in each of the holes corresponding to the number to be called and turning the disk. ∎  a plate or disk on a radio, stove, washing machine, or other piece of equipment that is tuned to select a wavelength or setting.• v. (di·aled, di·al·ing; Brit. di·alled, di·al·ling) [tr.] call (a telephone number) by turning a disk with numbered holes or pressing a set of buttons: he dialed room service | [intr.] company employees dial out from their office. ∎  (dial something up) gain access to a service using a telephone line: plans to enable customers to dial up videos from their living room. ∎  indicate or regulate by means of a dial: you're expected to dial in volume and tone settings.

dial instrument to tell the time of day by the shadow cast by the sun. XV. Obscure deriv. of medL. diālis, f. diēs day; see -AL 1.