Definition of turnsole

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