ETYM Pref. a- (for of) + kin.
1. Related by blood; SYN. blood-related, cognate, consanguine, consanguineous, kin.
2. Similar or related in quality or character; SYN. kindred, related.

Pertaining to or being a device or signal that is continuously varying in strength or quantity, such as voltage or audio, rather than based on discrete units, such as the binary digits 1 and 0. A lighting dimmer switch is an analog device because it is not based on absolute settings. Compare digital (definition 2).
(of a quantity or device) Changing continuously; by contrast a digital quantity or device varies in series a of distinct steps. For example, an analog clock measures time by means of a continuous movement of hands around a dial, whereas a digital clock measures time with a numerical display that changes in a series of discrete steps.

ETYM Latin analogous, Greek, according to a due ratio, proportionate; ana + logos ratio, proportion. Related to Logic.
1. Similar or correspondent in some respects though otherwise dissimilar; SYN. correspondent.
2. (Biology) Corresponding in function but not in evolutionary origin.

(Electronics) Of a circuit or device having an output that is proportional to the input; SYN. analog, linear.