Translation

だまされやすい / 信じ込みやすい / うぶな

Meaning

Gullible describes someone who is too ready to believe what others say and is easy to trick. It is usually negative or mildly critical, not a compliment for being kind. Do not confuse it with credible, which means believable.

Examples

• 彼はうますぎる投資話を信じるほどだまされやすくありません。
  He is not gullible enough to believe that investment pitch.
• その詐欺師はだまされやすい高齢者を狙いました。
  The scammer targeted gullible elderly people.