1 [C] [usu.sing] one of the two lines around the earth that are 23° 27ˈ north (the Tropic of Cancer)and south (the Tropic of Capricorn)of the line around the middle of the earth (the equator) 回归线（地球赤道南北各23度27分处的纬度圈，北边的叫北回归线，南边的叫南回归线） ☞picture at earth 见earth插图

2 the tropics [pl] the part of the world that is between these two lines, where the climate is hot and wet 热带（地区） ➔tropical /-kl ||; -kḷ/ adj tropical fruit 热带水果