The policeman called for 'backup' [=called for other police to come and help him] because the suspect was carrying a gun.
There was a traffic 'backup' [=('Brit') 'tailback'] for miles on the road because of the accident.
His role on the team is to be a 'backup' to the regular quarterback.
(..) Vasquez must be shitting herself. Shitting herself, or Walker is shitting himself and shoveling his shit on her shit. Bob, I'm planning on eating. Do we have a backup on the docket? You're on that, right, Frank? Yeah, I'm working with my staff-- Republicans are gonna ram this up our ass. (..)2013 TvShow: House of Cards Title: Chapter 2 Season: 1 Episode 2