Spiral operculum
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. [1913 Webster]

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. [1913 Webster]

3. (Geom.) Of or pertaining to a spiral; like a spiral. [1913 Webster]

{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. [1913 Webster]


The Collaborative International Dictionary of English. 2000.

Look at other dictionaries:

  • 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. [1913 Webster] 2. Winding round a cylinder or imaginary axis, and at… …   The Collaborative International Dictionary of English

  • Spiral gear — 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. [1913 Webster] 2. Winding round a cylinder or imaginary axis,… …   The Collaborative International Dictionary of English

  • Spiral gearing — 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. [1913 Webster] 2. Winding round a cylinder or imaginary axis,… …   The Collaborative International Dictionary of English

  • Spiral shell — 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. [1913 Webster] 2. Winding round a cylinder or imaginary axis,… …   The Collaborative International Dictionary of English

  • Spiral spring — 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. [1913 Webster] 2. Winding round a cylinder or imaginary axis,… …   The Collaborative International Dictionary of English

  • Spiral wheel — 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. [1913 Webster] 2. Winding round a cylinder or imaginary axis,… …   The Collaborative International Dictionary of English

  • Operculum (gastropod) — Gastropod shell of the freshwater snail Viviparus contectus with corneous operculum in place …   Wikipedia

  • gastropod — /gas treuh pod /, n. 1. any mollusk of the class Gastropoda, comprising the snails, whelks, slugs, etc. adj. 2. Also, gastropodous /ga strop euh deuhs/. belonging or pertaining to the gastropods. [1820 30; < NL Gast(e)ropoda a class of mollusks.… …   Universalium

  • fish — fishless, adj. /fish/, n., pl. (esp. collectively) fish, (esp. referring to two or more kinds or species) fishes, v. n. 1. any of various cold blooded, aquatic vertebrates, having gills, commonly fins, and typically an elongated body covered with …   Universalium

  • Fish — /fish/, n. Hamilton, 1808 93, U.S. statesman: secretary of state 1869 77. * * * I Any of more than 24,000 species of cold blooded vertebrates found worldwide in fresh and salt water. Living species range from the primitive lampreys and hagfishes… …   Universalium

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