Turnsole \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}.
[1913 Webster]
2. (Chem.)
(a) Litmus. [Obs.]
(b) A purple dye obtained from the plant turnsole. See
def. 1
(d) .
[1913 Webster]