a spiral.

Geometry . the curve formed by a straight line drawn on a plane when that plane is wrapped around a cylindrical surface of any kind, esp. a right circular cylinder, as the curve of a screw. Equation

x a sin?, y a cos?, z b

Architecture .

a spiral ornament.

(in a Corinthian capital) either of two scrolls issuing from a cauliculus. Compare Corinthian ( def. 2 ) .

Anatomy . the curved fold forming most of the rim of the external ear.

Biochemistry . alpha helix.