Spiral

1. a. Anything which has a spiral form, as a spiral shell.
2. a. Winding or circling round a center or pole and gradually receding from it; as, the spiral curve of a watch spring.
3. a. Winding round a cylinder or imaginary axis, and at the same time rising or advancing forward; winding like the thread of a screw; helical.
4. a. Of or pertaining to a spiral; like a spiral.
5. a. A plane curve, not reentrant, described by a point, called the generatrix, moving along a straight line according to a mathematical law, while the line is revolving about a fixed point called the pole. Cf. Helix.

The word meanings were obtained from OPTED(The Online Plain Text English Dictionary), which is based on “The Project Gutenberg Etext of Webster’s Unabridged Dictionary” which is in turn based on the 1913 US Webster’s Unabridged Dictionary (See Project Gutenburg), as a text file.