Definition: spiral

Source: WordNet (r) 1.7

spiral
     adj : in the shape of a coil [syn: coiling, helical, spiraling,
            volute, voluted, whorled, turbinate]
     n 1: a plane curve traced by a point circling about the center
          but at ever-greater distances from it
     2: a curve that lies on the surface of a cylinder or cone and
        cuts the element at a constant angle [syn: helix]
     3: ornament consisting of a curve on a plane that winds around
        a center with an increasing distance from the center [syn:
         volute]
     4: a structure consisting of something wound in a continuous
        series of loops; "a coil of rope" [syn: coil, volute,
        whorl, helix]
     5: flying downward in a helical path with a large radius
     v 1: to wind or move in a spiral course:" the muscles and nerves
          of his fine drawn body were coiling for action,", "black
          smoke coiling up into the sky"; "the young people
          gyrated on the dance floor" [syn: gyrate, coil]
     2: form a spiral; "The path spirals up the mountain"
     3: move in a spiral or zigzag course [syn: corkscrew]

Source: Webster's Revised Unabridged Dictionary (1913)

Spiral \Spi"ral\, n. [Cf. F. spirale. See Spiral, a.]
   1. (Geom.) A plane curve, not re["e]ntrant, 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.

   2. Anything which has a spiral form, as a spiral shell.

   Equiangular spiral,a plane curve which cuts all its
      generatrices at the same angle. Same as Logarithmic
      spiral, under Logarithmic.

   Spiral of Archimedes, a spiral the law of which is that the
      generatrix moves uniformly along the revolving line, which
      also moves uniformly.

Spiral \Spi"ral\, a. [Cf. F. spiral. See Spire a winding
   line.]
   1. Winding or circling round a center or pole and gradually
      receding from it; as, the spiral curve of a watch spring.

   2. Winding round a cylinder or imaginary axis, and at the
      same time rising or advancing forward; winding like the
      thread of a screw; helical.

   3. (Geom.) Of or pertaining to a spiral; like a spiral.

   Spiral gear, or Spiral wheel (Mach.), a gear resembling
      in general a spur gear, but having its teeth cut at an
      angle with its axis, or so that they form small portions
      of screws or spirals.

   Spiral gearing, a kind of gearing sometimes used in light
      machinery, in which spiral gears, instead of bevel gears,
      are used to transmit motion between shafts that are not
      parallel.

   Spiral operculum, an operculum whih has spiral lines of
      growth.

   Spiral shell, any shell in which the whorls form a spiral
      or helix.

   Spiral spring. See the Note under Spring, n., 4.