1. (n.) A plant of the genus Heliotropium; heliotrope; -- so named because its flowers are supposed to turn toward the sun.

2. (n.) The sunflower.

3. (n.) A kind of spurge (Euphorbia Helioscopia).

4. (n.) The euphorbiaceous plant Chrozophora tinctoria.

5. (a.) Litmus.

6. (n.) A purple dye obtained from the plant turnsole. See def. 1 (d).