1. Small edible marine snail; steamed in wine or baked; SYN. winkle.
2. Edible marine gastropod; SYN. winkle.
(snail)
3. Any marine snail of the family Littorinidae, found on the shores of Europe and E North America. Periwinkles have a conical spiral shell, and feed on algae.

In botany, any of several trailing blue-flowered evergreen plants of the genus Vinca of the dogbane family Apocynaceae. They range in length from 20 cm/8 in to 1 m/3 ft.
The related Madagascar periwinkle Catharanthus roseus produces chemicals that inhibit the division of cells and are used to treat leukemia.
Commonly cultivated Old World woody herb having large pinkish to red flowers; SYN. rose periwinkle, Madagascar periwinkle, old maid, Cape periwinkle, red periwinkle, cayenne jasmine, Catharanthus roseus, Vinca rosea.
Chiefly trailing poisonous plants with blue flowers.

A light purplish blue.