Undercarriage

[Little_Girl]

The area between your legs. Your crotch.

[Tanya Shivari]

If you are a little pudgy, your gut may sag down when doing push ups or copulating. This can be particularly unattractive as during vigorous sex, it may swing from side to side, back and forth, much like a metronome. In extreme cases, the folds of fat, or female breasts, may slap together making a sound not dissimilar to the sound of a sealion performing for food at shows at many zoos. This noise is known as flap or tat slapping.

[Tanya Shivari]

Very simple. This is your pets fucking stomach.

[Julian]

the set of wheels and other parts that support a plane when it is on the ground and make it possible to take off and land

[Michiko]

A wheeled structure beneath an aircraft, typically retracted when not in use, that receives the impact on landing and supports the aircraft on the ground.