Of things: An apparatus, vessel, etc., used for collecting something (variously applied in technical use). So collector ring, collector shoe (see…

An apparatus for accumulating or increasing the intensity of an electric charge. (Cf. condense, v. 1c) (Now largely superseded by capacitor, n.)

British. A rechargeable battery, esp. one in a motor vehicle.

A device which stores electricity during part of an operation; a condenser.

= electrolytic capacitor n. at compounds.