Spiral /(?)/
Spi·ral
Spiral
a.
- 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. (Geom.)
Phrases & Compounds
- Spiral gear
- 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.
Spiral
n.
- 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. (Geom.)
- Anything which has a spiral form, as a spiral shell.
Phrases & Compounds
- 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.