The state, condition, or realm of being duped or deceived, or the group of people who are dupes.
From dupe (a person who is easily fooled) plus the suffix -dom (a state or domain), following English patterns like kingdom or freedom. The word reflects 18th-century wordplay.
The suffix -dom is incredibly productive in English—you can add it to almost any noun to create an abstract state, which is why we have dupedom, wisdom, and kingdom all working the same way.
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