Sill Plate (Mudsill) : Bottom horizontal member of an exterior wall frame which rests on top a foundation, sometimes called mudsill. Also sole plate, bottom member of an interior wall frame
Frank Mayhue, Home Building Manual, Construction Glossary from Home Building Manual, USA 1999. http://www.homebuildingmanual.com/Glossary.htm, (Home Bulid - Amer) {518}