(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"
certainty based on past experience; "he wrote the paper with considerable reliance on the work of other scientists"; "he put more trust in his own two legs than in the gun"
a statement that makes something comprehensible by describing the relevant structure or operation or circumstances etc.; "the explanation was very simple"; "I expected a brief account"
the act of explaining; making something plain or intelligible; "I heard his explanation of the accident"