the apparent deflection of a moving mass of water, air, etc. to the right in the Northern Hemisphere and to the left in the Southern Hemisphere
See Coriolis effect in American Heritage Dictionary 4
(kôrˌē-ōˈlĭs, kōrˌ-)
noun
The observed effect of the Coriolis force, especially the deflection of an object moving above the earth, rightward in the northern hemisphere and leftward in the southern hemisphere.