cathode

noun

1. 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. 2

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

3. 3

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

4. 4

   That electrode of a semiconductor device which is connected to the n-type material of a p-n junction.