(Internet) A certain image of a man displaying his unnaturally dilated anus.

(informal) Alternative form of yuppiness

A wave that is shoaling, and shallow when it hits land.

(US, military, nautical) A hospital corpsman. / (deprecated, US, military) An enlisted person in the U.S. Army who works as a field medic. / (medicine, military, nonstandard) A military medic.