Definition of "back up"

back up

verb
third-person singular simple present backs up, present participle backing up, simple past and past participle backed up
1. (idiomatic, intransitive) To move backwards, especially for a vehicle to do so.
  Quotations
  We expressed our readiness, and in ten minutes were in the station wagon, rolling rapidly down the long drive, for it was then after nine. […] As we reached the lodge we heard the whistle, and we backed up against one side of the platform as the train pulled up at the other.
  1897 December (indicated as 1898), Winston Churchill, chapter V, in The Celebrity: An Episode, New York, N.Y.: The Macmillan Company; London: Macmillan & Co., Ltd.
2. (idiomatic, transitive) To move a vehicle backwards.
3. (idiomatic, intransitive) To undo one's actions.
4. (idiomatic, intransitive) To reconsider one's thoughts.
5. (idiomatic, computing, transitive) To copy (data) so that it can be restored if the main copy is lost.
6. (idiomatic, transitive) To provide support or the promise of support to.
  Quotations
  Thank you for backing me up. I know it's not easy delivering bad news-especially to a friend-but sometimes it's the only way we can move forward and begin to heal.
  2017, BioWare, Mass Effect: Andromeda (Science Fiction), Redwood City: Electronic Arts, PC, scene: Update on Jaal
  Researching and corroborating facts to put in my script is one thing, but getting sources to back up the assertions of interviewed contributors can be quite another.
  2020 May 6, Tim Dunn, “The Architecture The Railways Built”, in Rail, page 76
7. (idiomatic, intransitive, cricket) For the non-striker to take a few steps down the pitch, in preparation to taking a run, just as the bowler bowls the ball.
8. (idiomatic, intransitive, cricket) For a fielder to position himself behind the wicket (relative to a team-mate who is throwing the ball at the wicket) so as to stop the ball, and prevent overthrows.
9. (idiomatic, intransitive, of a blockage) To halt the flow or movement of something.
10. (idiomatic, intransitive, informal) To fill up because of a backlog.
  Quotations
  WAITRESS: Hurry up with those drinks, Lucy. We're backing up. (Grabs the drinks LUCY has poured.) What are you doing? These are regular. They all ordered large.
  1995, "Oubliette" (episode of The X-Files TV series)

Definition of "back up"

back up

verb

Quotations

Quotations

Quotations