n. n. A plant of the genus Heliotropium; heliotrope; -- so named because its flowers are supposed to turn toward the sun.n. The sunflower.n. A kind of spurge (Euphorbia Helioscopia).n. The euphorbiaceous plant Chrozophora tinctoria.n. n. Litmus.n. A purple dye obtained from the plant turnsole. See def. 1 (d).