Window at the side of fast food places where you can get food (of some description) without leaving your car. Also sometimes a place where you can get good drugs without leaving your car, if you know the right stuff to order. Primarily a North American thing, in tune with the American way of conducting as much of life as possible from the car.
I don't want a sit-down meal tonight, let's just get something at the drive-thru.
A device fast food places came up with during the `80s to serve lazy fatasses who are too fat or lazy to walk from the parking lot to the counter. Essentially a window on the side of the building where you get your special six patty big mac served between three hashbrowns instead of buns.
The short version of saying, "I'm too lazy to get out of my car."
Generally used large families, who order more than $50 worth of food, and then expect it to be ready in twenty seconds, because they believe the machines are magical and will cook faster because they used the drive thru.
A sexual position, similar to doggie-style, in which the couple are standing up, and, at the moment of climax, the partner in the rear pushes the partner in front over, causing them to fall and get be-spunked. In its truest form, the drive-thru should only take a few seconds.
I took her to the drive-thru last night and gave her exact change!