trĭquē̆trus, a, um, adj., having three corners, three-cornered, triangular.
I In gen.: triquetra aliis, aliis quadrata, Lucr. 4, 653: ager (opp. quadratus), Col. 5, 2, 1: figura (opp. quadrata), Plin. 2, 25, 23, § 93: (Britannia) insula naturā triquetra, Caes. B. G. 5, 13: Martis sidus numquam stationem facere Jovis sidere triquetro, i. e. distant by a third of the zodiac , Plin. 2, 17, 15, § 77; also as subst.: trĭquē̆trum , i, n., the trinal aspect , that in which a planet’s longitude differs by one-third of a circle from the earth’s : in triquetro, id. 2, 15, 12, § 59; 2, 18, 16, § 80.—
II In partic., as adj. prop. , of or belonging to the island of Sicily , Sicilian : orae, Lucr. 1, 717; Sil. 5, 489: tellus, Hor. S. 2, 6, 55; cf. Quint. 1, 6, 30.