luxury (n.) Look up luxury at Dictionary.com
c. 1300, "sexual intercourse;" mid-14c., "lasciviousness, sinful self-indulgence," from Old French luxurie "debauchery, dissoluteness, lust" (Modern French luxure), from Latin luxuria "excess, luxury, extravagance, profusion; delicacy" (source also of Spanish lujuria, Italian lussuria), from luxus "excess, extravagance, magnificence," probably a figurative use of luxus (adj.) "dislocated," which is related to luctari "wrestle, strain" (see reluctance).

Meaning "sensual pleasure" is late 14c. Lost its pejorative taint 17c. Meaning "habit of indulgence in what is choice or costly" is from 1630s; that of "sumptuous surroundings" is from 1704; that of "something enjoyable or comfortable beyond life's necessities" is from 1780. Used as an adjective from 1916.