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.
Any of the seats in the rear of a vehicle.
A lesser or inferior position; a position of deliberate noninvolvement, in which decision-making or leadership is left to others.