[adjective] fraught with uncertainty or doubt; "they were doubtful that the cord would hold"; "it was doubtful whether she would be admitted"; "dubious about agreeing to go" Synonyms:doubtful
[adjective] open to doubt or suspicion; "the candidate's doubtful past"; "he has a dubious record indeed"; "what one found uncertain the other found dubious or downright false"; "it was more than dubitable whether the friend was as influential as she thought"- Karen Horney Synonyms:doubtful, dubitable, in question
[adjective] not convinced; "they admitted the force of my argument but remained dubious"