unwary

/ʌnˈwɛri/
adjective
  1. Not cautious or alert; likely to be surprised or tricked.
    • An unwary hiker might step on a snake hidden in the tall grass.
    • The unwary driver did not notice the ice on the road until it was too late.
    • The scam artist targeted unwary tourists who were not familiar with the city.
Antonyms
What does "unwary" mean? | whatsthatwordmean | whatsthatwordmean