extravagance

Concise Oxford English Dictionary © 2008 Oxford University Press:
extravagant /ɪkˈstravəg(ə)nt, ɛk-/

▶adjective

• 1 lacking restraint in spending money or using resources.

  ■ resulting from or showing this: extravagant gifts.

• 2 exceeding what is reasonable or appropriate: extravagant claims.

– derivatives
extravagance noun,
extravagancy noun,
extravagantly adverb.

– origin ME (in the sense ‘unusual, unsuitable’): from med. L. extravagant-, extravagari ‘diverge greatly’, from L. extra- ‘outside’ + vagari ‘wander’.