noun a small constellation situated between aries and andromeda.
2. triangle ·noun a figure bounded by three lines, and containing three angles.
3. triangle ·noun a draughtsman's square in the form of a right-angled triangle.
4. triangle ·noun a small constellation near the south pole, containing three bright stars.
5. triangle ·noun a kind of frame formed of three poles stuck in the ground and united at the top, to which soldiers were bound when undergoing corporal punishment, now disused.
6. triangle ·noun an instrument of percussion, usually made of a rod of steel, bent into the form of a triangle, open at one angle, and sounded by being struck with a small metallic rod.