suspicious in WordNet English dictionary

1. not as expected
   "there was something fishy about the accident"; "up to some funny business"; "some definitely queer goings-on"; "a shady deal"; "her motives were suspect"; "suspicious behavior"
   fishy  funny  shady  suspect  suspicious 
   
2. openly distrustful and unwilling to confide
   leery  mistrustful  suspicious  untrusting  wary