nounplinthĭumPLINTHIVM☆ KeepMeaninga hollow square figureLewis & Short 1879ModernAs printed, 1879PLINTHIUMLEWIS & SHORTPLINTHIUMplinthĭum, ii, n., = πλίνθιον, I. a hollow square figure, a kind of sundial, Vitr. 9, 9.Read the whole entry