(computer science) a copy of a file or directory on a separate storage device; "he made a backup in case the original was accidentally damaged or erased"
an accumulation caused by clogging or a stoppage; "a traffic backup on the main street"; "he discovered a backup in the toilet"
someone who is appointed or elected to an office and who holds a position of trust; "he is an officer of the court"; "the club elected its officers for the coming year"