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.
(..) Grid's secure. Kill it. All readings are flat-lined. Get a visual. We're losing power! Get the backup generators online. We're working on it. That thing fried every single circuit! Trying to backup generators. Here we go! Everybody out, now! (..)2014 Godzilla