back up
• provide support for someone or something.
• "his mother backed him on up everything"
• make a spare copy of data or a disk.
• (of vehicles) form into a queue due to congestion.
• "the traffic began to back up"
• move or drive backwards.
• "she backed up until she found herself against the wall"
• (of running water) accumulate behind an obstruction.
backup
noun
• help or support.
• "no police backup could be expected"
• a copy of a file or other item of data made in case the original is lost or damaged.
• "make a backup of any important files"
• an accumulation of something caused by a blockage, as in traffic or water.
• "there are long backups on all routes"
