winding or circling round a center or pole and gradually receding from it; as, the spiral curve of a watch spring.-winding round a cylinder or imaginary axis, and at the same time rising or advancing forward; winding like the thread of a screw; helical.-of or pertaining to a spiral; like a spiral.-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.-anything which has a spiral form, as a spiral shell.