Definitions
1.nounA subsidiary entrance to a building or house at its rear, normally away from the street.
2.nounA means of access, often secret and unprotected, to something.
3.nounA secret means of access to a program or system.
4.nounA rear side door of a car, or at the back of a van.
5.nounThe anus, generally used in reference to anal sex.
6.nounThe rear side of the hole, furthest from the golfer.
7.verbTo attempt to accomplish by indirect means, especially when direct means are proscribed.
8.verbTo 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.
9.adjectiveThe path of a pitch which starts outside and then slides over the plate."He has a nasty back door slider."
10.adjectiveAchieved through indirect means.