D defs.my
Entry 2 senses Webster, 1913

Questionable

/kwĕs'-chən-əb-əl/ · Ques·tion·a·ble · IPA /ˈkwɛst͡ʃənəbl̩/
01 a. Admitting of being questioned; inviting, or seeming to invite, inquiry.
  1. 1.
    Admitting of being questioned; inviting, or seeming to invite, inquiry.[R.]
    “Thou com'st in such a questionable shape That I will speak to thee.” Shak.
  2. 2.
    Liable to question; subject to be doubted or called in question; problematical; doubtful; suspicious.
    “It is questionable whether Galen ever saw the dissection of a human body.T.” — Baker.