from The American Heritage® Dictionary of the English Language, 4th Edition

  • n. A curve on a plane that winds around a fixed center point at a continuously increasing or decreasing distance from the point.
  • n. A three-dimensional curve that turns around an axis at a constant or continuously varying distance while moving parallel to the axis; a helix.
  • n. Something having the form of such a curve: a spiral of black smoke.
  • n. Printing A spiral binding.
  • n. The course or flight path of an object rotating on its longitudinal axis.
  • n. A continuously accelerating increase or decrease: the wage-price spiral.
  • adj. Of or resembling a spiral.
  • adj. Circling around a center at a continuously increasing or decreasing distance.
  • adj. Coiling around an axis in a constantly changing series of planes; helical.
  • adj. Printing Relating to or having a spiral binding: a spiral notebook.
  • intransitive v. To take a spiral form or course.
  • intransitive v. To rise or fall with steady acceleration.
  • transitive v. To cause to take a spiral form or course.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. A curve that is the locus of a point that rotates about a fixed point while continuously increasing its distance from that point.
  • n. A helix.
  • adj. Helical, like a spiral
  • v. To move along the path of a spiral or helix.
  • v. To increase continually.

from the GNU version of the Collaborative International Dictionary of English

  • adj. Winding or circling round a center or pole and gradually receding from it.
  • adj. Winding round a cylinder or imaginary axis, and at the same time rising or advancing forward; winding like the thread of a screw; helical.
  • adj. Of or pertaining to a spiral; like a spiral.
  • n. A plane curve, not reëntrant, 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.
  • n. Anything which has a spiral form, as a spiral shell.

from The Century Dictionary and Cyclopedia

  • Of or pertaining to a spire or coil; like a spire; pointed or shaped like a spire.
  • Winding around a fixed point or center, and continually receding from it, like a watchspring; specifically, in conchology, making a number of turns about the columella or axis of the shell; whorled.
  • Winding and at the same time rising or advancing like a screw-thread: more accurately helical or helicoidal.
  • n. In geometry, a plane curve which runs continuously round and round a fixed point, called the center, with constantly increasing radius vector, so that the latter is never normal to the curve; also, a part of such a curve in the course of which the radius from the center describes 360°.
  • n. A helix or curve which winds round a cylinder like a screw.
  • n. A spiral spring.
  • n. In wool, one of the curls or convolutions in wool-fiber, the number of which in a unit of length is made the basis of an estimate of its quality for manufacturing.
  • n. In zoology and anatomy, a spiral formation, as of a univalve, of the cochlea, etc.
  • To make spiral; cause to move spirally.
  • To assume a spiral form; move in a spiral course.
  • n. A loop in a railroad line used to overcome steep grades in a mountainous region by carrying the line through a continuously rising curve.
  • n. of a point: The origin of coördinates O corresponds to v = o, and the asymptotic points, P′ , P1, round which the curve goes in an ever-closing spiral, correspond to v = ±∞. The intrinsic equation, expressing the relation between the arc σ (measured from O)and the inclination φ of the tangent at any point to the axis of x, is φ = ½πσ.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • n. a structure consisting of something wound in a continuous series of loops
  • n. a curve that lies on the surface of a cylinder or cone and cuts the element at a constant angle
  • n. a plane curve traced by a point circling about the center but at increasing distances from the center
  • n. ornament consisting of a curve on a plane that winds around a center with an increasing distance from the center
  • adj. in the shape of a coil
  • v. to wind or move in a spiral course
  • n. a continuously accelerating change in the economy
  • n. flying downward in a helical path with a large radius
  • v. move in a spiral or zigzag course
  • v. form a spiral


from The American Heritage® Dictionary of the English Language, 4th Edition

Medieval Latin spīrālis, of a spiral, from Latin spīra, coil; see spire2.



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