The rear, back, or unseen portion (of something).
The processing of spent fuel from a nuclear reactor into reusable materials.
That part of a hardware or software system that is farthest from the user; the internals rather than the user interface.
The latter end of any given time, especially the latter part of the year; autumn; late autumn.
Money paid on a contingent deferred basis, for example, as a proportion of the profits or revenue of a work.
Used other than figuratively or idiomatically: see back, side.
The back side of an estate: the backyard and outbuildings behind a main house, especially (UK dialect, euphemistic) an outhouse.
The reverse or opposite of anything.
A person's buttocks.
Used other than figuratively or idiomatically: see back, side.
Approaching an obstacle backward