suspicious
1 apprehensive, distrustful, doubtful, jealous, leery (slang) mistrustful, sceptical, suspecting, unbelieving, wary
2 dodgy (Brit., Austral., & N.Z. informal) doubtful, dubious, fishy (informal) funny, irregular, of doubtful honesty, open to doubt or misconstruction, queer, questionable, shady (informal) suspect
Antonyms
1 believing, credulous, gullible, open, trustful, trusting, unsuspecting, unsuspicious
2 above board, beyond suspicion, not open to question, open, straight, straightforward, unquestionable, upright