a. Bot. [f. TETRAGON or late L. tetragōn-us tetragonal + -OUS.] Having four angles; = TETRAGONAL a. 2.
1760. J. Lee, Introd. Bot., II. xxii. (1765), 125. Seed, a single one, oblong, often tetragonous.
1870. Hooker, Stud. Flora, 245. Convolvulus arvensis,… peduncle … 4-gonous.
1872. Oliver, Elem. Bot., App. 310. [Common Wheat] Inflorescence spicate,… tetragonous.
