refuse to acknowledge; disclaim knowledge of; responsibility for, or association with; "Her husband disavowed her after 30 years of marriage and six children"
(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"