1. (

• doubtful ,
• dubious

) 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" ;

2. (

• doubtful ,
• dubious ,
• dubitable ,
• in_question

) 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 ;

3. (

• dubious

) not convinced; "they admitted the force of my argument but remained dubious" ;