doubtful
1 adj If it is doubtful that something will happen, it seems unlikely to happen or you are uncertain whether it will happen.
For a time it seemed doubtful that he would move at all...
2 adj If you are doubtful about something, you feel unsure or uncertain about it.
(=dubious)
I was still very doubtful about the chances for success...
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doubtfully adv
(=dubiously)
Keeton shook his head doubtfully.
3 adj If you say that something is of doubtful quality or value, you mean that it is of low quality or value., (disapproval)
(=dubious)
...selling something that is overpriced or of doubtful quality...
4 adj If a sports player is doubtful for a match or event, he or she seems unlikely to play, usually because of injury. (JOURNALISM)