Definition of unthinkable adjective from the Oxford Advanced American Dictionary

     

    unthinkable

     adjective
    adjective
    NAmE//ʌnˈθɪŋkəbl//
     
    unthinkable (for somebody) (to do something)unthinkable (that…)
     
    jump to other results
  1. 1impossible to imagine or accept synonym inconceivable
  2. 2 It was unthinkable that she could be dead. opposite thinkable
the unthinkable
 
jump to other results
 
noun [singular] Suddenly the unthinkable happened and he pulled out a gun. The time has come to think the unthinkable (= consider possibilities that used to be unacceptable).
See the Oxford Advanced Learner's Dictionary entry: unthinkable