Lewis & Short

† plinthis, ĭdis, f., = πλινθίς (a square tile).

  1. I. A square; in architect., a square base, a plinth, for plinthus, Vitr. 3, 3, 2; in land-surveying, for plinthus, Hyg. Condit. Agror. p. 210 Goes.
  2. II. Plur.: plinthĭ-des, a register in the hydraulic organ, Vitr. 10, 8, 8; v. pleuritis.