/hee"lee euh trohp', heel"yeuh-/ or, esp. Brit., /hel"yeuh-/ , n.
1. any hairy plant belonging to the genus Heliotropium, of the borage family, as H. arborescens, cultivated for its small, fragrant purple flowers.
2. any of various other plants, as the valerian or the winter heliotrope.
3. any plant that turns toward the sun.
4. a light tint of purple; reddish lavender.
5. Survey. an arrangement of mirrors for reflecting sunlight from a distant point to an observation station.
6. bloodstone.
[ 1580-90; héliotrope heliotropium heliotrópion (see HELIO-, -TROPE); cf. ME elitropium, elitropius, OE eliotropus ]