levity

LEV'ITY, n. [L. levitas, from levis, light; connected perhaps with Eng. lift.]

1. Lightness; the want of weight in a body, compared with another that is heavier. The ascent of a balloon in the air is owing to its levity, as the gas that fills it is lighter than common air.

2. Lightness of temper or conduct; inconstancy; changeableness; unsteadiness; as the levity of youth.

3. Want of due consideration; vanity; freak. He never employed his omnipotence out of levity or ostentation.

4. Gaiety of mind; want of seriousness; disposition to trifle. The spirit of religion and seriousness was succeeded by levity.