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Definition of "back up" [back• up]

  • To move backwards, especially for a vehicle to do so. (verb)
  • To move a vehicle backwards. (verb)
  • To undo one's actions. (verb)
  • To reconsider one's thoughts. (verb)
  • To copy (data) as a security measure. (verb) : Text is available under the Creative Commons Attribution-ShareAlike License

Use "back up" in a sentence
  • "He quickly pulled his hands apart and looked back up to see one of the landing control crewmen, a short, wiry man named Al Dietz, walking toward him."
  • "Heading back up the conveyor to the canopy-side transport station?"
  • "Climbing back up the steps and continuing west, we find some tumbledown shacks at the top of the path leading to the slipway."