a. A flexible bag designed to be inflated with hot air or with a gas, such as helium, that is lighter than the surrounding air, causing it to rise and float in the atmosphere.
b. Such a bag with sufficient capacity to lift and transport a suspended gondola or other load.
c. Such a bag shaped like a figure or object when inflated; an inflatable.
2. A usually round or oblong inflatable rubber bag used as a toy or decoration.
3. Medicine An inflatable device that is inserted into a body cavity or structure and distended with air or gas for therapeutic purposes, such as angioplasty.
a. See speech bubble.
b. See thought bubble.
5. A balloon payment.
v. bal·looned, bal·loon·ing, bal·loons
1. To ascend or ride in a balloon.
2. To expand or swell out like a balloon. See Synonyms at bulge.
3. To increase or rise quickly: expenses ballooning out of control.
To cause to expand by or as if by inflating: unforeseen expenditures that ballooned the deficit.
Suggestive of a balloon, as in shape: balloon curtains.
[French ballon, from Italian dialectal ballone, augmentative of balla, ball, of Germanic origin; see bhel-2 in the Appendix of Indo-European roots.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.