inconceivable
adj.adj. impossible to imagine or believe. You use this when something is so strange or extreme that your mind cannot accept it as true.
adj. impossible to comprehend or grasp mentally; unthinkable. Often used to emphasize the extreme nature of a situation or a high degree of improbability.
It is inconceivable that he would lie to us.
Before the invention of the internet, the idea of instant global communication was inconceivable to most people.
The scale of the disaster was so vast that the total cost of reconstruction seemed inconceivable to the local government officials tasked with the recovery.
From in- + conceivable.
Typically used as a predicative adjective after linking verbs like 'be', 'seem', or 'become'.
It is inconceivable for me that...It is inconceivable to me that...When expressing who finds something impossible to believe, use the preposition 'to' rather than 'for'.