lighter than air

/ˈlaɪtər ðən ˈɛr/
adjective
  1. Describing a gas or aircraft that is less dense than the surrounding air, so it floats or rises.
    • Lighter-than-air aircraft like zeppelins were popular in the early 20th century.
    • Hot air balloons work because heated air is lighter-than-air.
    • Helium is a lighter-than-air gas used to fill balloons and blimps.
  2. Extremely light in weight or feeling; very airy or delicate.
    • She wore a lighter-than-air summer dress that floated in the breeze.
    • His mood became lighter-than-air after he finished his exams.
    • The soufflé was so fluffy it felt lighter-than-air.
Antonyms
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