The parts of a book that appear after the main portion of the body text, including the afterword, index and bibliography; the end matter.

Having a broken back. / (nautical, of a ship) Drooping at each end because of a damaged spine. / Decrepit, weakened.

(rugby) a back whose primary job it is to exploit space created by the inside backs, i.e. the outside centre, both wingers, and the full back

(rugby) the scrum-half and the fly-half

(finance) Having assets as collateral.

(squash, racquetball) The wall at the back of a racquetball or squash court, directly opposite the front wall. / Used other than figuratively or idiomatically: see back, wall.

plural of back-double

A favourite route through a town or city, often used as a shortcut.

To tie or fasten behind.

simple past tense and past participle of tie back