The Collaborative International Dictionary
Inconvincible
Inconvincible \In`con*vin"ci*ble\, a. [L. inconvincibilis. See In- not, and Convince.] Not convincible; incapable of being convinced.
None are so inconvincible as your half-witted people.
--Gov. of the
Tongue.
Wiktionary
inconvincible
a. Incapable of being convinced.