Shotgun

If a group of friends is going somewhere in a car, someone may "call shotgun" to claim the front seat, next to the driver. This seat is desirable because the person sitting in it controls the radio and temperature, and usually has more leg room than the backseat passengers. The idiom comes from the old west when the person next to the driver carried a shotgun to protect the driver and passengers from attack from thieves.

EXAMPLE: As soon as Eugene suggested that we go out for ice cream, April called shotgun.