/ bəˈluːn; NAmE / noun , verb
■ noun
1.
a small bag made of very thin rubber that becomes larger and rounder when you fill it with air or gas. Balloons are brightly coloured and used as decorations or toys :
to blow up / burst / pop a balloon
—compare trial balloon
2.
(also hot-ˈair balloon ) a large balloon made of strong material that is filled with hot air or gas to make it rise in the air, usually carrying a basket for passengers
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IDIOMS
- when the balloon goes up
—more at lead (II)
■ verb [ v ]
1.
balloon (out / up) to suddenly swell out or get bigger :
Her skirt ballooned out in the wind.
2.
(usually go ballooning ) to travel in a hot-air balloon as a sport
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WORD ORIGIN
late 16th cent. (originally denoting a game played with a large inflated leather ball): from French ballon or Italian ballone large ball.