People driving during a tornado are told to find low ground and lay flat,facedown, with their hands covering their head.

VOA: special.2011.04.19

They can develop as flat, discolored areas of skin or as raised growths, often with a rough surface.

VOA: special.2010.07.06

The artist draws an image with oily ink onto a piece of stone or other flat surface.

VOA: special.2009.09.02

The runway is built on a flat stretch of land on a hill, with a sheer drop on both sides.

VOA: standard.2010.05.23