ques ‧ tion ‧ a ‧ ble /ˈkwestʃ ə nəb ə l/ BrE AmE adjective
[ Word Family: noun : ↑ question , questioning, ↑ questioner , ↑ questionnaire ; adjective : ↑ questionable ≠ ↑ unquestionable , ↑ questioning ≠ ↑ unquestioning , ↑ unquestioned ; adverb : ↑ unquestionably , ↑ questioningly ≠ ↑ unquestioningly ; verb : ↑ question ]
1 . not likely to be true or correct:
The statistics are highly questionable.
it is questionable whether
It is questionable whether the taxpayer receives value for money.
2 . not likely to be good, honest, or useful:
I suspected that his motives for helping us were questionable.
He was a man of questionable character.