The middle seat in a truck, el camino, or car. Normally where the girl sits when you have 2 men and 1 woman in a front-seat formation. Occasionally, however, the awkward situation will arise where you have 3 males who must sit in the same front seat.

1. The default beliefs installed when you were a child.

2. An unexamined position you absorbed from your environment growing up.

1. The rear seat on a motorcylce because that's where the bitch rides.
2. The #1 spot on someone's myspace top 8 because that's were everyone feels obligated to put thier gf.

The passenger seat on a motorcycle, called so because the biker's bitch rode on it.

The middle seat of a vehicle. Got it's name for being known to seat bitches, or women.

the middle seat in the back seat of a car. often when it's a group of 3 people fitting in the backseat and you're the one in the middle

In context of the game shotgun , the bitch seat is the seat that is last to be claimed after shotgun is called. It is the worst seat in the car, usually the middle back seat, although any backseat in the car can be the bitch seat if it has, for example, a malfunctioning window or crappy apholstery.