WordNet sense 1 (a compound made artificially by chemical reactions):

synthetic substance

WordNet sense 2 (not of natural origin; prepared or made artificially):

man-made, semisynthetic

WordNet sense 3 (artificial as if portrayed in a film):

celluloid

WordNet sense 4 (contrived by art rather than nature):

unreal

WordNet sense 5 (not genuine; imitating something superior):

counterfeit, imitative

WordNet sense 6 (involving or of the nature of synthesis (combining separate elements to form a coherent whole) as opposed to analysis):

synthetical