gullible
/ˈɡʌlɪbl̩/adjective
Too ready to believe what others say, and therefore easy to trick.
Example sentence
- “She's so gullible that she believed the email saying she'd won a million dollars.”
The old prank claims 'gullible' is not in the dictionary, testing exactly the trait it names. 'Naive' blames inexperience; 'gullible' blames the person.