a. (sb.) Geom. [f. TRI- + post-cl.L. līneālis LINEAL.] next. Also as sb. a trilineal figure.
1745. trans. Gregory’s Astron., I. (1726), I. 45. The infinitely small trilineal Figures.
1807. Hutton, Course Math., II. 115. To each add the trilineal IAE.
1891. Pall Mall G., 20 Oct., 6/1. Dr. Barrett … addressed the students,… he said, ‘Never mind about trilineal co-ordinates, go in for music.’
