triangular

As an adjective triangular

is shaped like a triangle.

As a noun vocalis is

a triangular band of muscle, inserted into the vocal process of the arytenoid cartilage, and into the adjacent portion of its anterior surface; it lies parallel with the vocal ligament, to which it is adherent.

As an adjective triangular

is shaped like a triangle.

As a noun piebaldism is

(medicine) a rare autosomal dominant disorder of melanocyte development, whose common characteristics include a congenital white forelock, scattered normally-pigmented and hyperpigmented macules, and a triangular depigmented patch on the forehead.

As an adjective triangular

is shaped like a triangle.

As a noun didal is

(obsolete) a kind of triangular spade.