Adjective
incapable of being conceived or considered
Source: WordNetIt is unthinkable for a Frenchman to arrive at middle age without having syphilis and the Cross of the Legion of Honor. André Gide
It seemed unthinkable for me to leave the world forever before I had produced all that I felt called upon to produce. Ludwig van Beethoven
If there is a State, there must be domination of one class by another and, as a result, slavery; the State without slavery is unthinkable – and this is why we are the enemies of the State. Mikhail Bakunin
Physical love is unthinkable without violence. Milan Kundera
Reality prior to my language exists as an unthinkable thought.... life precedes love, bodily matter precedes the body, and one day in its turn language shall have preceded possession of silence. Clarice Lispector
A good politician is quite as unthinkable as an honest burglar. H. L. Mencken