A reserve or substitute. / (computing) A copy of a file or record, stored separately from the original, that can be used to recover the original if it is destroyed or damaged.

Standby, reserve or extra. / (computing) That is intended as a backup. / Supporting, reinforcing; (music) of or related to accompaniment

Misspelling of back up.

plural of backup

(computing) Capable of being backed up.

(nonstandard, proscribed) Misconstruction of backed up

(music) A member of a group of singers who provide backup vocals to a song

(music) The chorus and other words and sounds sung by backup vocalists to provide accompaniment to a song / (music) The people who sing these vocals

(computing) A backup method where only the information that has changed since a previous backup is saved.

plural of backup vocalist