Meaning of extratropical cyclone

ex'tra•trop'i•cal cy'clone

Pronunciation: (ek'stru-trop'i-kul, ek"-), [key]
  1. any large-scale, cyclonic storm that is not a tropical cyclone, esp. the common frontal cyclone of the middle and high latitudes.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.