n.
- a plane figure with three straight sides and three angles.
- a thing shaped like a triangle.
▸N. Amer. a drawing instrument in the form of a right-angled triangle.
▸
(triangles)
historical a frame of three halberds joined at the top to which a soldier was bound for flogging.
- a musical instrument consisting of a steel rod bent into a triangle, sounded with a rod.
- another term for eternal triangle (see eternal).
- a small brownish moth of oak and beech woods.
[Heterogenea asella.]
Etymology
ME: from OFr. triangle or L. triangulum, neut. of triangulus (see tri-, angle1).