1. naive and easily deceived or tricked (Freq. 1) - at that early age she had been gullible and in love • Syn: fleeceable, green • Similar to: naive, naif • Derivationally related forms: gullibility 2. easily tricked because of being too trusting - gullible tourists taken in by the shell game • Similar to: unwary • Derivationally related forms: gullibility