adjective

not genuine or true (used in a disapproving manner when deception has been attempted).

a bogus insurance claim

fake,faked,spurious,false,fraudulent,sham,deceptive,misleading,pretended,counterfeit,forged,feigned,simulated,artificial,imitation,mock,make-believe,fictitious,dummy,quasi-,pseudo,ersatz,phoney,fakey,pretend,dud,put-on,cod