helix

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Mathematics A three-dimensional curve that lies on a cylinder or cone, so that its angle to a plane perpendicular to the axis is constant.
• noun A spiral form or structure.
• noun Anatomy The folded rim of skin and cartilage around most of the outer ear.
• noun Architecture A volute on a Corinthian or Ionic capital.
• intransitive verb To move or position (something) into the shape of a helix.
• intransitive verb To have the shape of a helix.
• intransitive verb To move along a helical course; spiral.

from The Century Dictionary.

• noun A spiral line, as of wire in a coil; a winding, or something that is spiral; a circumvolution; specifically, in geometry, the curve assumed by a right line drawn on a plane when that plane is wrapped round a cylindrical surface of any kind, especially a right cylinder, as the curve of a screw-thread; also, a curve on any developable surface which becomes a right “line when the surface is developed into a plane, as a conical helix.
• noun In architecture, any spiral, particularly a small volute or twist under the abacus of the Corinthian capital; also, a volute of the Ionic capital.
• noun In electricity, a coil of wire, as that surrounding the core of an electromagnet.
• noun In anatomy: The prominent curved fold which forms most of the rim or margin of the outer ear. See second cut under ear.
• noun The cochlea of the inner ear.
• noun [capitalized] [NL.] In conchology, the representative genus of Helicidæ and Helicinæ.

from the GNU version of the Collaborative International Dictionary of English.

• noun (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.
• noun (Arch.) A caulicule or little volute under the abacus of the Corinthian capital.
• noun (Anat.) The incurved margin or rim of the external ear. See Illust. of Ear.
• noun (Zoöl.) A genus of land snails, including a large number of species.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun mathematics A curve on the surface of a cylinder or cone such that its angle to a plane perpendicular to the axis is constant; the three-dimensional curve seen in a screw or a spiral staircase.
• noun architecture A small volute under the abacus of a Corinthian capital.
• noun anatomy The incurved rim of the external ear.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a curve that lies on the surface of a cylinder or cone and cuts the element at a constant angle
• noun a structure consisting of something wound in a continuous series of loops
• noun type genus of the family Helicidae