(1):

(n.) A small constellation situated between Aries and Andromeda.

(2):

(n.) 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.

(3):

(n.) A small constellation near the South Pole, containing three bright stars.

(4):

(n.) 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.

(5):

(n.) A draughtsman's square in the form of a right-angled triangle.

(6):

(n.) A figure bounded by three lines, and containing three angles.