Translate triangle | into French | into German | into Italian | into Spanish Definition of triangle
noun
a plane figure with three straight sides and three angles:an equilateral triangle a thing shaped like a triangle:a small triangle of grass a situation involving three people or things, especially an emotional relationship involving a couple and a third person with whom one of them is involved. a musical instrument consisting of a steel rod bent into a triangle and sounded by being struck with a small steel rod. a frame used to position the balls in pool and snooker. a drawing instrument in the form of a right triangle. (
triangles)
historical a frame of three halberds joined at the top to which a soldier was bound for flogging.