What is the meaning of Back_door?

A subsidiary entrance to a building or house at its rear, normally away from the street.

A means of access, often secret and unprotected, to something.

A secret means of access to a program or system.

A rear side door of a car, or at the back of a van.

The anus; anal sex.

The rear side of the hole, furthest from the golfer.

The path of a pitch which starts outside and then slides over the plate.

Achieved through indirect means.

Requiring consecutive cards on the turn and river to be achieved.

To attempt to accomplish by indirect means, especially when direct means are proscribed.

To enter a tube by accelerating from behind; to surf into an already formed hollow wave, in contrast to the normal method of slowing to allow a surfable wave to form.

To add a backdoor (a secret means of access) to a program or system.

Source: wiktionary.org