Definition of "extravagant"

The extravagant and erring spirit hies / To his confine.

c. 1599–1602 (date written), William Shakespeare, “The Tragedie of Hamlet, Prince of Denmarke”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act I, scene i]

There appears something nobly wild and extravagant in great natural geniuses.

1711 September 14 (Gregorian calendar), [Joseph Addison; Richard Steele et al.], “MONDAY, September 3, 1711”, in The Spectator, number 160; republished in Alexander Chalmers, editor, The Spectator; a New Edition, […], volume II, New York, N.Y.: D[aniel] Appleton & Company, 1853

The half-dozen pieces […] were painted white and carved with festoons of flowers, birds and cupids. […] The bed was the most extravagant piece. Its graceful cane halftester rose high towards the cornice and was so festooned in carved white wood that the effect was positively insecure, as if the great couch were trimmed with icing sugar.

1963, Margery Allingham, chapter 1, in The China Governess‎

According to this saga of intellectual-property misanthropy, these creatures [patent trolls] roam the business world, buying up patents and then using them to demand extravagant payouts from companies they accuse of infringing them. Often, their victims pay up rather than face the costs of a legal battle.

2013 June 8, “Obama goes troll-hunting”, in The Economist, volume 407, number 8839, page 55

some of the Quakers were extravagant and foolish

1834–1874, George Bancroft, History of the United States, from the Discovery of the American Continent