Synonyms: unwary
Definition: not alert to danger or deception
Usage: the shrieks of unwary animals taken by surprise; some thieves prey especially on unwary travelers; seduce the unwary reader into easy acquiescence- O.J.Campbell
Similar words: gullible
Definition: easily tricked because of being too trusting
Usage: gullible tourists taken in by the shell game
Similar words: unguarded
Definition: displaying or feeling no wariness
Usage: an unguarded remark