balloon

UK: /bəˈluːn/ US: /bəˈlun/ ,(bə lo̅o̅n′)

WordReference Random House Learner's Dictionary of American English © 2025

bal•loon /bəˈlun/   n. 

[countable]
1. Games a rubber bag that can be inflated with gas, used as a toy.
2. Aeronautics a bag of strong, light material filled with a gas lighter than air so as to rise through the air.

v. [no obj]

3. Aeronautics to ride in a balloon.
4. to puff out like a balloon.
5. to increase at a rapid rate:
   His weight ballooned when he quit smoking.

adj. [before a noun]

6. puffed out like a balloon:
   balloon sleeves.

bal•loon•ist, n. [countable]

WordReference Random House Unabridged Dictionary of American English © 2025

bal•loon  (bə lo̅o̅n′), n. 

1. a bag made of thin rubber or other light material, usually brightly colored, inflated with air or with some lighter-than-air gas and used as a children's plaything or as a decoration.
2. Aeronautics a bag made of a light material, as silk or plastic, filled with heated air or a gas lighter than air, designed to rise and float in the atmosphere and often having a car or gondola attached below for carrying passengers or scientific instruments.
3. (in drawings, cartoons, etc.) a balloon-shaped outline enclosing words represented as issuing from the mouth of the speaker.
4. Architecture an ornamental ball at the top of a pillar, pier, or the like.
5. Wine, Ceramics a large, globular wineglass.
6. Chemistry a round-bottomed flask.

v.i. 

7. Aeronautics to go up or ride in a balloon.
8. to swell or puff out like a balloon.
9. to multiply or increase at a rapid rate:
   Membership has ballooned beyond all expectations.

v.t. 

10. to fill with air;
    inflate or distend (something) like a balloon.

adj. 

11. puffed out like a balloon:
    balloon sleeves.
12. Banking, Business [Finance.] (of a loan, mortgage, or the like) having a payment at the end of the term that is much bigger than previous ones.

• Upper Italian
• Middle French ballon
• Langobardic; see ball¹) + -one augmentative suffix; or
• Upper Italian ballone, equivalent. to ball(a) (
• 1570–80

bal•loon′like′, adj. 

Collins Concise English Dictionary © HarperCollins Publishers::

balloon / bəˈluːn/ noun

1. an inflatable rubber bag of various sizes, shapes, and colours: usually used as a plaything or party decoration
2. a large impermeable bag inflated with a lighter-than-air gas, designed to rise and float in the atmosphere. It may have a basket or gondola for carrying passengers, etc
   See also barrage balloon
3. a circular or elliptical figure containing the words or thoughts of a character in a cartoon
4. a kick or stroke that propels a ball high into the air
5. (as modifier): a balloon shot
6. a round-bottomed flask
7. a large rounded brandy glass
8. a large sum paid as an irregular instalment of a loan repayment
9. (as modifier): a balloon loan
10. an inflatable plastic tube used for dilating obstructed blood vessels or parts of the alimentary canal
11. (as modifier): balloon angioplasty
12. go down like a lead balloon ⇒ to be completely unsuccessful or unpopular
13. when the balloon goes up ⇒ when the trouble or action begins

verb

1. (intransitive) to go up or fly in a balloon
2. (intransitive) to increase or expand significantly and rapidly: losses ballooned to £278 million
3. to inflate or be inflated; distend; swell: the wind ballooned the sails
4. (transitive) to propel (a ball) high into the air

Etymology: 16th Century (in the sense: ball, ball game): from Italian dialect ballone, from balla, of Germanic origin; compare Old High German balla ball¹

balˈlooning noun

balˈloonist noun

balˈloon-ˌlike adjective