periwinkle

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Any of several small, often edible marine snails, especially of the genus Littorina, having thick, cone-shaped, whorled shells.
2. n. The shell of any of the periwinkles.
3. n. Any of several shrubby, trailing, evergreen plants of the genus Vinca, especially V. minor, having glossy, dark green, opposite leaves and flowers with a blue, funnel-shaped corolla. Also called myrtle.
4. n. Any of several erect herbs of the genus Catharanthus, especially C. roseus, having flowers with a rose-pink or white salverform corolla and a closed throat.
5. n. A pale purplish blue.

Century Dictionary and Cyclopedia

1. n. A plant of the genus Vinca, most often one or other of the familiar garden species, v. major, the larger, and v. minor, the lesser periwinkle. These are natives of southern Europe, trailing plants with deep-colored evergreen leaves and blue flowers, in v. minor varying to white—often known as myrtles. The small species is the more hardy, and hence the more common northward. v. herbacea, another European species, differs from these in that its tops die down annually. v. rosea, sometimes called Madagascar periwinkle though native of tropical America, is an erect plant with continuously blooming showy rose-purple or white flowers, excellent for bedding or in the greenhouse.
2. n. A kind of seasnail; any member of the family Littorinidæ, and especially of the genus Littorina. See cuts under Littorina and Littorinidæ.
3. n. One of several large whelks or conch-shells, as Busycon (Fulgur) carica, Sycotypus canaliculatus, and various species of Purpura, as P. ostrina, P. lapillus, P. floridana: commonly called winkles or wrinkles. They are pests in the oyster-beds.
4. n. In Australia, a name given to the gastropod Turbo undulatus.

Wiktionary

1. n. A color with bluish and purplish hues, somewhat light.
2. adj. Of pale bluish purple colour.
3. n. A mollusk of genus Littorina.

GNU Webster's 1913

1. n. (Zoöl.) Any small marine gastropod shell of the genus Littorina. The common European species (Littorina littorea), in Europe extensively used as food, has recently become naturalized abundantly on the American coast. See littorina.
2. n. (Bot.) A trailing herb of the genus Vinca.

WordNet 3.0

1. n. commonly cultivated Old World woody herb having large pinkish to red flowers
2. n. edible marine gastropod
3. n. chiefly trailing poisonous plants with blue flowers
4. n. small edible marine snail; steamed in wine or baked