dubious
du-bi-ous
adjective
Causing doubt or suspicion; not to be relied upon or trusted.
"His claims about winning the lottery seemed dubious."
adjective
Hesitating or doubting; feeling uncertain about something.
"I was dubious about the success of the new plan."
Thesaurus
Synonyms: doubtful, uncertain, unsure, incertain, questionable, in question, dubitable, unconvinced