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.
(..) -Let's go. -Which one? -l don't know. -God. -Damn. l told you we should've called for backup. You know the Chief's gonna kill us, right? You know the Chief's gonna kill us, right? Let me give you guys a little tip. lf you're going to operate outside the channels... (..)2004 White Chicks
(..) Damn, Marcus, why you always got to pick the biggest dude? l don't know. l like a challenge. See, what did l tell you? We did it, right? Didn't l tell you? -No help. No backup. -You the man. We'll get all the credit. The biggest bust of our career. keys of pure.... -Vanilla ice cream? (..)2004 White Chicks