[trig] adj [ME, trusty, nimble, of Scand origin; akin to ON tryggr faithful; akin to OE treowe faithful--more at true] (1513) 1: stylishly or jauntily trim
2: extremely precise: prim 3 dial chiefly Brit: firm, vigorous
[2]trig n [by shortening] (ca. 1895): trigonometry