Levity

·noun Lack of steadiness or constancy; disposition to change; fickleness; volatility.

II. Levity ·noun Lack of gravity and earnestness in deportment or character; trifling gayety; frivolity; sportiveness; vanity.

III. Levity ·noun The quality of weighing less than something else of equal bulk; relative lightness, especially as shown by rising through, or floating upon, a contiguous substance; buoyancy;

— opposed to gravity.