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.
(..) Jake Peralta wants to see him. I'm not after him. I just need his help. Hello? I followed all your rules. I'm unarmed. I'm not wearing a wire. I came alone. There's no backup. Come on, man. I need your help to take down your brother. Doug Judy. The Pontiac Bandit. Hey, baby. Nice legs. (..)2017 TvShow: Brooklyn Nine-Nine Title: #DUPE# Season: 4 Episode 11