Wiktionary
n. (context electronics English) A circuit board that connects several connectors in parallel to each other, so that each pin of each connector is linked to the same relative pin of all the other connectors, forming a computer bus.
Wikipedia
A backplane (or "backplane system") is a group of electrical connectors in parallel with each other, so that each pin of each connector is linked to the same relative pin of all the other connectors, forming a computer bus. It is used as a backbone to connect several printed circuit boards together to make up a complete computer system. Backplanes commonly use a printed circuit board, but wire-wrapped backplanes have also been used in minicomputers and high-reliability applications.
Usage examples of "backplane".
It was life-size and perfectly reproduced, not at all ghostlike the way backplane!
He was only a backplanet lout, somewhat at a loss out here in mainstream civilization, as his experience during this voyage showed.
He really was a backplanet boy, having little knowledge of the appropriate ceremonies associated with this beverage but conscious of his ignorance.