An Etymological Dictionary of Astronomy and Astrophysics

Any circulatory wind system in the atmosphere in which the motion is anticlockwise in the northern hemisphere (that is in the same sense as that of Earth) and clockwise in the southern hemisphere, around a center of low pressure.

Etymology (EN): From Gk. kyklon “moving in a circle, whirling around,” pr.p. of kykloun “move in a circle, whirl,” from kyklos “circle,” cognate with Pers. carx→ cycle.

Etymology (PE): Carxand “moving in a circle,” from carxidan→ rotate, from carx, → cycle.