plinthis

ĭdis, f.
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.—
II. Plur.: plinthĭ-des, a register in the hydraulic organ, Vitr. 10, 8, 8; v. pleuritis.
Lewis & Short
A Latin Dictionary, 1879
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