adjective

characterized by or reflecting a state of moral or cultural decline.

a decaying, decadent Britain

dissolute,dissipated,degenerate,corrupt,depraved,louche,rakish,shameless,sinful,unprincipled,immoral,licentious,wanton,abandoned,unrestrained,profligate,intemperate,fast-living,sybaritic,voluptuary,epicurean,hedonistic,pleasure-seeking,indulgent,self-indulgent

noun

a person who is luxuriously self-indulgent.

for half a million dollars, he offers rich decadents the chance to lead a deadly safari