Mudsill /(?)/

Mud·sill

Mudsill

n.
  1. 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.
  2. Fig.: A person of the lowest stratum of society; -- a term of opprobrium or contempt. [Southern U. S.]