An atmospheric system characterized by the rapid inward circulation of air masses about a low-pressure center, usually accompanied by stormy, often destructive weather. Cyclones circulate counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere.
A violent tropical storm, especially one originating in the southwestern Pacific Ocean or Indian Ocean.
A violent rotating windstorm.
Any of various devices using centrifugal force to separate materials.
[From Greek kuklōn, present participle of kukloun, to rotate, from kuklos, circle; see kwel-1 in Indo-European roots.] cy·clon'ic (-klŏn'ĭk), cy·clon'i·cal adj.