Tropical cyclone
热带气旋

A tropical cyclone is a storm system characterized by a large low-pressure center and numerous thunderstorms that produce strong winds and heavy rain. Tropical cyclones are classified into three main groups, based on intensity: tropical depressions, tropical storms, and a third group of more intense storms, whose name depends on the region.
热带气旋指的是一种风暴系统，其特征是有一个低压中心，大量的雷暴及伴随而来的狂风暴雨。根据强度的不同，热带气旋可以划分为三类：热带低压，热带风暴，以及更强的、在不同地区名字有所不同的一类风暴。

Tropical depression
热带低压

A tropical depression is an organized system of clouds and thunderstorms with maximum sustained winds of less than 17 metres per second(61 km/h). It has no eye and does not typically have the spiral shape of more powerful storms.
热带低压是指最大风速低于17米/秒（61千米/时）的风暴系统。热带低压没有风眼，也不像更强的风暴系统那样呈螺旋状。

Tropical storm
热带风暴

A tropical storm is an organized system of strong thunderstorms with maximum sustained winds between 17 metres per second and 32 metres per second(117 km/h). At this point, the distinctive cyclonic shape starts to develop, although an eye is not usually present.
热带风暴是指最大风速在17米/秒到32米/秒（117千米/时）之间的强风暴系统。独特的气旋结构已经开始形成，但是还没有风眼。

Hurricane/Typhoon
飓风/台风

A hurricane or typhoon is a system with sustained winds of at least 33 metres per second(119 km/h). A cyclone of this intensity tends to develop an eye. A tropical cyclone occurring in the western Pacific or Indian oceans is called a typhoon, while that originating in the Atlantic Ocean or Caribbean Sea or eastern regions of the Pacific Ocean is called a hurricane.
飓风/台风是指风速至少达到33米/秒（119千米/时）的风暴系统。达到这种强度的气旋发展出了风眼。在西太平洋和印度洋上生成的热带气旋被称为“台风”，而起源于大西洋、加勒比海或太平洋东部的热带气旋则被称为“飓风”。
(沪江小编：说白了typhoon和hurricane就是同一个人在不同地区的不同名字而已啊……)

Eye
风眼

The eye is a region of mostly calm weather found at the center of strong tropical cyclones. The eye of a storm is a roughly circular area and typically 30–65 km in diameter. It is surrounded by the eyewall, a ring of towering thunderstorms where the most severe weather of a cyclone occurs.
“风眼”是强热带气旋中心的一块平静区域，通常呈圆形，直径30-65千米。风眼四周环绕着“眼壁”，即一圈剧烈雷暴区域，通常是整个热带气旋中天气最恶劣的区域。