| Mudsill (n.) The lowest sill of a structure, usually embedded in the soil; the lowest timber of a house; also, that sill or timber of a bridge which is laid at the bottom of the water. See Sill. Thesaurus Entries base, basement, basis, bearing wall, bed, bedding, bedrock, doorsill, doorstone, floor, flooring, fond, footing, foundation, fundament, fundamental, ground, grounds, groundsel, groundwork, hardpan, mudsill, pavement, principle, radical, riprap, rock bottom, rudiment, seat, solid ground, solid rock, stereobate, stylobate, substratum, substruction, substructure, terra firma, threshold, underbuilding, undercarriage, undergirding, underpinning, understruction, understructure, window sill |