questionable

adjective3

1. •
   Problematic; open to doubt or challenge.

   • It is questionable if the universe is open or closed.
2. •
   Of dubious respectability or morality.

   • […] he had a love of money—a sort of acquisitiveness, that led him into questionable dealings. — 1920
3. •
   (no longer used) Inviting questions; inviting inquiry.

   • Thou com'st in such a questionable shape / That I will speake to thee. — 1599