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.
(..) Doomsday Adam, the guy that he was going to check out, just turned up dead. Okay, uh, I got the address. I'm turning around. Send backup. Fuck! Fuck! Fuck! Fuck! Dispatch, this is lieutenant Debra Morgan. I need all available units (..)2011 TvShow: Dexter Title: Talk to the Hand Season: 6 Episode 11