A dupe or duplication comes in two forms. It can be either a program, which you run, or a method, in which instructions are passed around the internet on how to 'dupe'.
There are also a few types of dupes:
- Item dupe: a duplication method or program that dupes or copies item(s) you have
- Gold dupe: a duplication method or program that dupes or copies an amount of gold you have
Duping within the World of Warcraft is a breach of the Terms of Use, and can get your account permanently suspended.