ˈtərnˌsōl noun
( -s )
Etymology: Middle English turnesole, from Middle French tournesol, from Old Italian tornasole, from tornare to turn (from Medieval Latin) + sole sun, from Latin sol (accusative solem ) — more at turn , solar
1. : any of several plants whose flowers or stems are supposed to follow the movement of the sun:
a. : heliotrope 1b
b. : sunflower
c. : sun spurge
d. : a double-flowered tulip ( Tulipa suaveolens ) of southern Russia
2. : a European annual herb ( Chrozophora tinctoria ) of the family Euphorbiaceae the juice of which is turned blue by ammonia
3.
a. : a purple dye obtained from the turnsole (sense 2)
b. : litmus