3.A rotating column of air usually accompanied by a funnel-shaped downward extension of a cumulonimbus cloud and having a vortex several hundred yards in diameter whirling destructively at speeds of up to500 miles(800 kilometers) per hour.
龙卷风，陆龙卷一种纵向的气旋，伴随有倒漏斗形的积雨云，涡流直径达几百码，以每小时五百英里（八百公里）的速度移动，其旋转具有极大的毁坏性
