the.com/dado

means A groove cut into wood (or the lower section of an interior wall treated as a distinct panel) designed to hold another piece snugly or display a decorative band.

from From Italian 'dado,' meaning 'die' or 'cube' (as in dice), which traced back to Latin 'datum,' meaning 'given' — the same root that gives us 'data.' In architecture, the 'dado' first named the cube-like middle section of a pedestal, sitting between base and cornice like a die resting on a table. Carpenters later borrowed the word for the groove or the wainscot-height band on a wall, since both echo that same squared-off, block-like middle zone.