Imaginability
the GNU version of the Collaborative International Dictionary of English
noun.
Capacity for imagination.
Wiktionary, Creative Commons Attribution/Share-Alike License
noun.
The quality of being
imaginable
.
Word Usage
"No-one would nowadays identify the two (except, perhaps, for certain quasi-realists and anti-realists), but the view that imaginability is a solid test for possibility has been strongly defended."
Antonyms
Words with the opposite meaning
unimaginability