TRIANGULAR a.
Oblong or elongated, and having three lateral angles; as, a triangular seed, leaf, or stem. Triangular compasses, compasses with three legs for taking off the angular points of a triangle, or any three points at the same time. -- Triangular crab (Zoöl.), any maioid crab; -- so called because the carapace is usually tr…
UNDULATORY a.
n of waves, which successively rise or swell rise or swell and fall; pertaining to a propagated alternating motion, similar to that of waves. Undulatory theory, or Wave theory (of light) (Opt.), that theory which regards its various phenomena as due to undulations in an ethereal medium, propagated from the radiant with…