Webster's Revised Unabridged Dictionary · 1913

Levity

Levity (lev"i*ty) , noun

[Latin levitas, from levis light in weight; akin to levare to raise. See Lever, n.]

1.
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.
He gave the form of levity to that which ascended; to that which descended, the form of gravity. — Sir. W. Raleigh
This bubble by reason of its comparative levity to the fluidity that incloses it, would ascend to the top. — Bentley
2.
Lack of gravity and earnestness in deportment or character; trifling gayety; frivolity; sportiveness; vanity.
A spirit of levity and libertinism. — Atterbury
He never employed his omnipotence out of levity. — Calamy
3.
Lack of steadiness or constancy; disposition to change; fickleness; volatility.
The levity that is fatigued and disgusted with everything of which it is in possession. — Burke