noun

1. An electrode, of a cell or other electrically polarized device, through which a positive current of electricity flows outwards (and thus, electrons flow inwards). It usually, but not always, has a positive voltage.

2. (by extension) The electrode at which chemical reduction of cations takes place, usually resulting in the deposition of metal onto the electrode.

3. The electrode from which electrons are emitted into a vacuum tube or gas-filled tube.