n.

1. 【氣】氣旋[U]
   Tropical low pressure fronts easily become cyclone, which are called typhoons or hurricanes depending on the location.

   熱帶的低氣壓容易形成氣旋，而依地區的不同稱之為颱風或颶風。

2. 旋風；暴風；龍卷風[C]

n.

1. Meteorology  a system of winds rotating inwards to an area of low barometric pressure; a depression.
2. a tropical storm.