What does "extravagance" mean?

Extravagance: The state of being extravagant, wild, or prodigal beyond bounds of propriety or duty; want of moderation; excess; especially, undue expenditure of money; vaid and superfluous expense; prodigality; as, extravagance of anger, love, expression, imagination, demands. Some verses of my own, Maximin and Almanzor, cry vengeance on me for their extravagance. Dryden. The income of three dukes was enough to supply her extravagance. Arbuthnot.