|1.||geometry one of several plane curves formed by a point winding about a fixed point at an ever-increasing distance from it. Polar equation of Archimedes spiral:r = aθ; of logarithmic spiral: log r = aθ; of hyperbolic spiral:rθ = a, (where a is a constant)|
|2.||another name for helix|
|3.||something that pursues a winding, usually upward, course or that displays a twisting form or shape|
|4.||Compare spin a flight manoeuvre in which an aircraft descends describing a helix of comparatively large radius with the angle of attack within the normal flight range|
|5.||economics a continuous upward or downward movement in economic activity or prices, caused by interaction between prices, wages, demand, and production|
|6.||having the shape of a spiral|
|—vb , -rals, -ralling, -ralled, -rals, -raling, -raled|
|7.||to assume or cause to assume a spiral course or shape|
|8.||(intr) to increase or decrease with steady acceleration: wages and prices continue to spiral|
|[C16: via French from Medieval Latin spīrālis, from Latin spīra a coil; see |
spiral spi·ral (spī'rəl)
Coiling or developing around an axis in a constantly changing series of planes; helical. n.
A structure in the shape of a coil. v. spi·raled or spi·ralled, spi·ral·ing or spi·ral·ling, spi·rals or spi·rals
To take the form or course of a spiral.