[ sahy-klohn ]
See synonyms for: cyclonecyclones on

  1. Meteorology. a large-scale, atmospheric wind-and-pressure system characterized by low pressure at its center and by circular wind motion, counterclockwise in the Northern Hemisphere, clockwise in the Southern Hemisphere.: Compare anticyclone, extratropical cyclone, subtropical cyclone, tropical cyclone.

  2. (not in technical use) tornado (def. 1).

  1. Also called cy·clone col·lec·tor [sahy-klohn kuh-lek-ter], /ˈsaɪ kloʊn kəˌlɛk tər/, cy·clone sep·a·ra·tor [sahy-klohn sep-uh-rey-ter]. /ˈsaɪ kloʊn ˌsɛp əˌreɪ tər/. Machinery. a device for removing small or powdered solids from air, water, or other gases or liquids by centrifugal force.

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Origin of cyclone

Introduced by British meteorologist Henry Piddington (1797–1858) in 1848, perhaps from Greek kyklôn “revolving” (present participle of kykloûn “to revolve,” verbal derivative of kýklos “wheel, ring, circle”; see cycle); apparently confused by Piddington with kýklōma “wheel, snake's coil”

Other words from cyclone

  • min·i·cy·clone, noun
  • pre·cy·clone, noun

Words that may be confused with cyclone

Words Nearby cyclone Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use cyclone in a sentence

British Dictionary definitions for cyclone (1 of 2)


/ (ˈsaɪkləʊn) /

  1. another name for depression (def. 6)

  2. a violent tropical storm; hurricane

Origin of cyclone

C19: from Greek kuklōn a turning around, from kukloein to revolve, from kuklos wheel

Derived forms of cyclone

  • cyclonic (saɪˈklɒnɪk), cyclonical or cyclonal, adjective
  • cyclonically, adverb

British Dictionary definitions for Cyclone (2 of 2)


/ (ˈsaɪkləʊn) /

  1. trademark Australian and NZ (of fencing) made of interlaced wire and metal

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for cyclone


[ klōn′ ]

  1. A large-scale system of winds that spiral in toward a region of low atmospheric pressure. A cyclone's rotational direction is opposite to that of an anticyclone. In the Northern hemisphere, a cyclone rotates counterclockwise; in the Southern hemisphere, clockwise. Because low-pressure systems generally produce clouds and precipitation, cyclones are often simply referred to as storms.♦ An extratropical cyclone is one that forms outside the tropics at middle or high latitudes. Extratropical cyclones usually have an organized front and migrate eastward with the prevailing westerly winds of those latitudes.♦ A tropical cyclone forms over warm tropical waters and is generally smaller than an extratropical cyclone. Such a system is characterized by a warm, well-defined core and can range in intensity from a tropical depression to a hurricane. Compare anticyclone.

  2. A small-scale, violently rotating windstorm, such as a tornado or waterspout. Not in scientific use.

a closer look

Technically, a cyclone is nothing more than a region of low pressure around which air flows in an inward spiral. In the Northern Hemisphere the air moves counterclockwise around the low-pressure center, and in the Southern Hemisphere the air travels clockwise. Meteorologists also refer to tropical cyclones, which are cyclonic low-pressure systems that develop over warm water. For a tropical cyclone to originate, a large area of ocean must have a surface temperature greater than 27 degrees Celsius (80.6 degrees Fahrenheit). Tropical cyclones are categorized based on the strength of their sustained surface winds. They may begin as a tropical depression, with winds less than 39 miles (63 kilometers) per hour. Tropical storms are identified and tracked once the winds exceed this speed. Severe tropical cyclones, with winds of 74 miles (119 kilometers) per hour or greater, are better known as hurricanes when they occur in the Atlantic Ocean and Gulf of Mexico, or as typhoons when they happen in the Pacific Ocean. Because the word cyclone broadly defines a kind of air flow, cyclones are not confined to our planet. In 1999 the Hubble Space Telescope photographed a cyclone more than 1,610 kilometers (1,000 miles) across in the northern polar regions of Mars.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Cultural definitions for cyclone


Any circular wind motion. A region of low atmospheric pressure. Also, a tropical storm.

Notes for cyclone

Cyclones can be a few feet across (“dust devils”) or can be major storm systems such as hurricanes, tornadoes, and typhoons.

Notes for cyclone

These winds move counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere. (See Coriolis effect.)

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.