noun

a fraudulent imitation of something else.

he knew the tapes to be counterfeits

fake,forgery,copy,reproduction,replica,imitation,likeness,lookalike,mock-up,dummy,substitute,fraud,sham,phoney,pirate,knock-off,rip-off,put-on,dupe

verb

imitate fraudulently.

my signature is extremely hard to counterfeit

fake,forge,copy,reproduce,replicate,imitate,simulate,feign,falsify,sham,pirate