Turn"sole` (?), n. [F. tournesol, It. tornasole; tornare to turn (LL. tornare) + sole the sun, L. sol. See Turn, Solar, a., and cf. Heliotrope.] [Written also turnsol.]
1. Bot. (a)
A plant of the genus Heliotropium; heliotrope; -- so named because its flowers are supposed to turn toward the sun.
(b)
The sunflower.
(c)
A kind of spurge (Euphorbia Helioscopia).
(d)
The euphorbiaceous plant Chrozophora tinctoria.
2. Chem. (a)
Litmus.
[Obs.] (b)
A purple dye obtained from the plant turnsole. See def. 1 (d).
© Webster 1913.