1. A flexible, nonporous bag inflated with a gas, such as helium, that is lighter than the surrounding air, that causes the bag to rise and float in the atmosphere. 2. Such a bag with sufficient capacity to lift a suspended gondola or other payload. 3. Any of variously shaped, brightly colored inflatable rubber bags used as toys. 4. A sac that is inserted into a body cavity or tube and distended with air or gas for therapeutic purposes, such as angioplasty. 5. A rounded or irregularly shaped outline containing the words that a character in a cartoon is represented to be saying. 6. To ascend or ride in a balloon. 7. bulge 8. To increase or rise quickly. 9. To cause to expand by or as if by inflating. 10. balloon curtains.
