DOUBTFUL

[adjective]The expression on her face was doubtful (= uncertain) and anxious as I was telling my story.The teacher is doubtful about having (= not certain that she wants to have) parents working as classroom assistants.Having a private education is a doubtful advantage in life. (= It might not be an advantage.)It is doubtful whether/if (= unlikely that) they ever reached the summit before they died.It was doubtful that the money would ever be found again.