doubtful 

  1. 形容詞
懷疑的, 疑惑的
不大可能的
可疑的, 令人生疑的
含糊的, 不明確的
難以預測的
(名聲等)不好的
(人)doubtful about/of ...(事):
對...表示懷疑的
對...持懷疑態度的
對...心存疑慮的

    同義字詞
distrustful,dubious,mistrustful,skeptical,suspicious,uncertain,unconvinced,undecided,unsettled,unsure
debatable,disputable,doubtable,dubious,dubitable,equivocal,fishy,problematic,problematical,queer,questionable,shady,shaky,suspect,suspicious
dubious,far-fetched,flimsy,improbable,questionable,unapt,unlikely
arguable,controvertible,debatable,disputable,doubtable,issuable,moot,negotiable,questionable

例句

  1. Ian Rush (groin) is also doubtful .
  2. Doubtful that you'd get in anywhere.
  3. In doubtful cases, images were re-read.
  4. I would say that his doubtful right now .
  5. The future of Pontiac was still doubtful .