helix

n.; pl. L. Helices E. Helixes [ L. helix, Gr. &unr_;, &unr_;, fr. &unr_; to turn round; cf. L. volvere, and E. volute, voluble. ] 1. (Geom.) A nonplane curve whose tangents are all equally inclined to a given plane. The common helix is the curve formed by the thread of the ordinary screw. It is distinguished from the spiral, all the convolutions of which are in the plane. [ 1913 Webster ]

2. (Arch.) A caulicule or little volute under the abacus of the Corinthian capital. [ 1913 Webster ]

3. (Anat.) The incurved margin or rim of the external ear. See Illust. of Ear. [ 1913 Webster ]

4. (Zool.) A genus of land snails, including a large number of species. [ 1913 Webster ]

☞ The genus originally included nearly all shells, but is now greatly restricted. See Snail, Pulmonifera. [ 1913 Webster ]