a. rare. [f. L. triangul-um TRIANGLE + -OID.] Resembling a triangle; of somewhat triangular form.
1876. Kellogg, in Arizona Miner, 3 March, 1/6. It [rattle weed] has a tall and leafy stem or stems in bunches from a common perennial root, leaflets many paired (twenty or more), stipules at the base of the leaves trianguloid membranous.
1879. J. Solis Cohen, Throat & Voice, iv. The vocal organ is contained in the larynx (larunx, top of the windpipe), an irregular prismatic or trianguloid funnel-shaped expansion of the air-passage, on top of the tubular windpipe (trachea), and continuous with it.
