1. unexplainable not able to be accounted for or made clear
  2. unobtainable not capable of being acquired
  3. unexceptionable completely acceptable; not open to reproach
  4. unascertainable not able to be ascertained; resisting discovery
  5. unsustainable not capable of being prolonged or continued
  6. inexpugnable incapable of being overcome, challenged or refuted
  7. inexplicable incapable of being explained or accounted for
  8. unexpendable not suitable to be expended
  9. unquestionable incapable of being questioned
  10. sustainable capable of being prolonged
  11. acceptable worthy of approval or satisfactory
  12. explainable capable of being understood
  13. ascertainable capable of being ascertained or found out
  14. unexportable not suitable for export
  15. inhospitable lacking cordiality and generosity toward guests or strangers
  16. obtainable capable of being acquired
  17. unquestionably without question
  18. exceptionable likely to cause objection or disapproval
  19. unattainable impossible to achieve
  20. inexpiable incapable of being atoned for