To move backwards from a certain position; SYN. back off, back down.
When you are explaining something, and you repeat something that you already said, you back up.
The ability of an expert system to try alternative solutions in an attempt to find an answer. The various alternatives can be viewed as branches on a tree: in backtracking, the program follows one branch and, if it reaches the end without finding what it seeks, backs up and tries another branch.
To make a copy of (a computer file) esp. for storage in another place as a security cop
1. When you walk backward, you backup. When you drive a vehicle in reverse, you back up or back the vehicle up.
2. When you make a claim or statement and then show people evidence or give them information proving that the claim or statement is true or correct, you back it up.
3. When you support people in a conflict or a confrontation, you back them up. When you support people by doing some work or a difficult assignment, you back them up
4. When you duplicate important information, such as a computer program or data, so that you will still have it if the original information is lost or damaged, you back it up.
5. When a piece of equipment or machinery is very important and another is kept available in case the one that is normally used fails, the second piece of equipment or machinery backs up the first.
6. When something backs up, it is being prevented from moving, progressing, or flowing normally