Spī'ral1, a.
(89), a. [Fr. spiral, Sp. espiral, It. spirale, Lat. as if spiralis, from spira, a coil, a spire. See SPIRE.]
Sense 1. Winding round a cylinder or other round body, or in a circular form, and at the same time rising or advancing forward; winding like a screw.
Sense 2. Pointed like a spire, or steeple. [Rare.]
Spiral gear or gearing, gearing consisting of wheels working together with their axes at an angle with each other double that of the direction of the teeth with the axis; — a kind of gearing sometimes used in light machinery instead of bevel gearing, to change the direction of motion. — Spiral wheel (Mach.), a wheel having its teeth cut at an angle with its axis, or so that they form small portions of screws or spirals.
