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.
(..) -Did you say "zebra"? -That's right. A zebra. Right in front of me. -Can I shoot it? -Negative. Then I'm going to need some backup. -Knicks lost again. -What are you going to do? Did that say "Grand Central Station" or "my aunt's constipation"? This is it. (..)2005 Madagascar