The term "dial" has several meanings, depending on its context.
1) In a general sense, it can refer to any circular scale or indicator that shows numerical values or other information, such as a gauge or meter. For example, one might adjust the dials on an audio amplifier to set the volume level.
2) It can also mean a rotary telephone button used for making selections or initiating calls. When pressed, it would connect the caller with the desired party.
3) In a more specific sense, "dial" can refer to the face of an analog watch, which typically features Arabic numerals or other markings arranged in a circular pattern. The hands of the watch move around this dial to indicate time.