Definition of arris piece in English:

arris piece

noun

rare, historical
  • A long or narrow piece of wood (or another building material) with a triangular cross-section used in various structural applications; specifically (Nautical and Shipbuilding) one used to fill a V-shaped gap formed by the meeting of two timbers in order to smooth the transition between them, such as between the rounded outer pieces of a made mast.

Origin

Early 18th century; earliest use found in William Sutherland (fl. 1711–1717).