(Meteorology)a system of winds rotating inwards to an area of low barometric pressure, with an anticlockwise (northern hemisphere) or clockwise (southern hemisphere) circulation; a depression (气象)旋风;龙卷风 ■another term for tropical storm 同 tropical storm
派生 cyclonic adjective cyclonically adverb 语源
mid 19th cent.: probably from Greek kuklōma 'wheel, coil of a snake', from kuklos 'circle'. The change of spelling from -m to -n is unexplained