unsuspecting

/ˈʌnsəˌspɛktɪŋ/

/ənsəsˈpɛktɪŋ/

If you're unsuspecting, you are innocent and trusting. An unsuspecting tourist will be blissfully unaware that the smiling old lady on the subway has stolen his wallet.

If you lack a sense of suspicion or distrust, especially in the face of some kind of danger, you're unsuspecting. A criminal's unsuspecting victims find themselves utterly surprised that they've been robbed, and an unsuspecting hiker wanders right into a bear's den. In both cases, a little bit of suspicion would have served them well.

Definitions of unsuspecting

1. adjective

   (often followed by 'of') not knowing or expecting; not thinking likely
   “an unsuspecting victim”

   “unsuspecting (or unaware) of the fact that I would one day be their leader”

   synonyms:

   incognizant, unaware

   (often followed by `of') not aware
2. adjective

   not suspicious
   “deceiving the unsuspecting public”

   synonyms: unsuspicious

   trustful, trusting

   inclined to believe or confide readily; full of trust