C 气球a large bag of strong light material filled with gas or heated air so that it can float in the air

　balloon　的意思是“气球”，可指玩具气球或装饰性气球，还可指实用的热气球。

　blow up a ～　吹气球
　fly a ～　放气球
　puncture a ～　刺破气球
　colored ～s　彩色气球
　in a ～　乘气球

　Many children like balloons.　许多孩子都喜欢气球。
　They have let fly multi-colored balloons.　他们放飞了五颜六色的气球。
　The balloon was invented before the plane.　热气球是在飞机发明之前发明的。

 ♣ go down like a lead balloon
　（讲话、建议等）未达到预期的效果，毫无作用　(of a remark, suggestion, etc.) fail to
　His jokes about woman drivers went down like a lead balloon.　他讲了不少女人驾车的笑话，但没人笑。
 ♣ when the balloon goes up
　厄运当头　when an unpleasant situation began
　I don't want to be around when the balloon goes up.　要出事了，我趁早离开是非之地。

　balloon　还可用作动词，意思是“乘气球上升；乘气球飞行”。例如：
　Let's go ballooning tomorrow.　我们明天去乘气球飞行吧。