Pĕl'e-coid, n.

noun

n. [Gr. πέλεκυς, a hatchet, and εἶδος, form.] (Geom.) A figure, somewhat hatchet-shaped, bounded by a semicircle and two inverted quadrants, and equal in area to the square A B C D inclosed by the chords of the four quadrants. [Written also pelicoid.] Math. Dict.

A curved, four-sided figure with dashed lines connecting its labeled points A, B, C, and D. — Pelecoid.