Naive - lacking in experience, too willing to believe
The night Eve (naive) was deceived by the serpent into eating the forbidden fruit. She was too willing to believe the snake was telling the truth.
Example of naïve in a sentence
He was so naive he believed the stranger would pay back the £10 he loaned him.
Janet was naive enough to think she would get the job even though she had no qualifications or experience.
The naive old lady was the perfect target for a financial scam.