46 minutes ago, drpaladin said:

Pediment and impediment come from different origins and are not connected in meaning.

Well I'll be dipped in s*** and rolled in peanuts. I was sure that pediment was going to be the one derived from ped/pes, but color me educated. 

You'll think a pediment is a serious impediment in an earthquake when it lands on your face.

OK, I'm thinking about pediments. First thing that comes to mind is Geology 101 at Eastern Washington State College (now Eastern Washington University) where pediments were being discussed. Quick look up pediments in the geological sense. The Italian word pedamento entered English meaning "foundation, basework, footing." Along the front of steep mountains in the Western United States, the Andes of South America, and surrounding monadnocks or inselbergs in South Africa there is gently sloping bedrock covered with a thin layer of gravels. These should not be confused with merged alluvial fans which are made up of material eroded from canyons of the escarpments.