1. n. a potential victim of a confidence trick; a patsy. The crooks found a good dupe and started their scheme.
2. tv. to trick someone; to swindle someone. I did not try to dupe you. It was an honest mistake.
3. n. a duplicate; a copy. I’ve got a dupe in the files.
4. tv. to duplicate something; to copy something. Just a minute, I have to dupe a contract for the boss.