shot·gun 
(shŏtgŭn′)
(shŏtgŭn′)n.
1. A smoothbore gun that fires shot over short ranges. Also called scattergun.
2. Football An offensive formation, used especially for passing, in which the quarterback receives the snap several yards behind the line of scrimmage.
adj.
1. Of, relating to, or using a shotgun.
2. Obtained by or involving coercion: a shotgun compromise.
3. Covering a wide range in a haphazard or ineffective manner: shotgun methods of testing the hypothesis that wasted time and money.
4. Having the rooms joined in a line from front to back: a shotgun house, a shotgun apartment
tr.v. shot·gunned, shot·gun·ning, shot·guns
1. To shoot at with a shotgun.
2. To drink (a can of beer or other beverage) quickly through a hole punched near the bottom of the can.
interj.
Idiom: Used to claim the front passenger seat of a vehicle before a trip has started.
ride shotgun
To sit in the front passenger seat of a vehicle during a trip.
[Adjective, from the fact that the shot from a shotgun fired through the front door could go out the back door without encountering any intervening obstacles. Interj. and idiom, probably from shotgun messenger, a private armed guard who protected strongboxes and other valuable shipments on stagecoaches and rode in the seat next to the driver.]