■ noun
1》 a plane figure with three straight sides and three angles.
2》 a thing shaped like a ~.
↘ N. Amer. a drawing instrument in the form of a right-angled ~.
↘( ~s ) historical a frame of three halberds joined at the top to which a soldier was bound for flogging.
3》 a musical instrument consisting of a steel rod bent into a ~, sounded with a rod.
4》 another term for eternal ~ (see eternal ).
5》 a small brownish moth of oak and beech woods. [ Heterogenea asella .]
Origin
ME: from OFr. ~ or L. triangulum , neut. of triangulus (see tri- , angle 1 ).