backup
noun
"If the goalkeeper is injured, we have a backup."
°(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.
"After the power failure, we had to restore the database from backup."
adjective
"I am only a backup player."
°(computing) That is intended as a backup.
"Make a backup copy of that file."
synonyms: reserve, stand-in, spare, substitute more» , block, blockage, extra, reserve, spare, standby