"I.P." means "intellectual property" to most folks, but to car designers, it stands for "instrument panel." Like all design specialties, car designers have their own language, which can sound strange to the layperson.

In forthcoming entries for this "Car Design Terms that Sound Like Cocktail Names" series, we'll highlight some of the more bizarre terms auto designers use when describing particular design features.

We'll start with "tumblehome," a term borrowed from nautical design. Tumblehome is something you cannot see in a side view sketch of a car, only from the front or rear; it refers to the way (and amount) that a vehicle's side windows curve or slant in towards the center of the vehicle. This van, for instance, can be said to have no or little tumblehome:

Image by TONYWONG, C.C. A-SA 4.0

This car has tumblehome:

Image by TONYWONG, C.C. A-SA 4.0

In general, the sportier the car, the more pronounced the tumblehome.

The Lamborghini Countach has extreme tumblehome.

The counterpart term to tumblehome is "turn under," which refers to the car's sides below the beltline sloping in towards the center as it gets closer to the ground. The Countach has a fair amount of turn under. However, "turn under" doesn't sound like a cool cocktail so it doesn't make the cut here.