extravagant

from The American Heritage® Dictionary of the English Language, 5th Edition.

• adjective Exceeding reasonable bounds: synonym: excessive.
• adjective Unreasonably high in cost; exorbitant.
• adjective Lavish or imprudent in spending money.
• adjective Extremely abundant; profuse.
• adjective Archaic Straying beyond limits or bounds; wandering.

from The Century Dictionary.

• Wandering beyond bounds or out of the regular course; straying.
• Exceeding just or reasonable limits; excessive; exorbitant; unreasonable; lavish: as, the demands or desires of men are often extravagant; extravagant living or expenditure.
• Not comprised within ordinary limits of truth, probability, or propriety; irregular; wild; fantastic: as, extravagant flights of fancy.
• Exceeding necessity or prudence in expenditure; wasteful; prodigal; profuse: as, an extravagant purchase; an extravagant man.
• Synonyms and Inordinate, exorbitant, unconscionable, absurd.
• Extravagant, Profuse, Lavish, Wasteful, Prodigal, reckless. Extravagant and prodigal refer more often to habits or character, the others to acts. All apply to that which is immoderate or unreasonable in quantity or degree; wasteful to that which is injuriously so. One may be extravagant or wasteful with a small sum; it requires a large sum to enable one to be profuse, lavish, or prodigal. Lavish is stronger than profuse. Prodigal, perhaps from association with the prodigal son of Luke xv. 11-32, suggests most of immorality and reprobation. All these words have lighter figurative uses.
• noun One who wanders about; a vagrant; a vagabond.
• noun One who is confined to no general rule; an eccentric.
• noun plural A part of the body of canon law: as, the Extravagants of John XXII. and the Extravagantes communes of other popes: so called because they treated of matters not in the decretals (extra decretum vagabantur).
• noun A collection of Jewish traditions, published at the end of the second century.

from the GNU version of the Collaborative International Dictionary of English.

• noun One who is confined to no general rule.
• noun (Eccl. Hist.) Certain constitutions or decretal epistles, not at first included with others, but subsequently made a part of the canon law.
• adjective obsolete Wandering beyond one's bounds; roving; hence, foreign.
• adjective Exceeding due bounds; wild; excessive; unrestrained.
• adjective Profuse in expenditure; prodigal; wasteful.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adjective exceeding the bounds of something
• adjective extreme
• adjective exorbitant

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• adjective recklessly wasteful
• adjective unrestrained, especially with regard to feelings