inconvincible

in·con·vinc·i·ble

 (ĭn′kən-vĭn′sə-bəl)
adj.
Impossible to convince: was inconvincible as to the validity of our idea.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

inconvincible

(ˌɪnkənˈvɪnsəbəl)
adj
refusing or not able to be convinced
ˌinconˌvinciˈbility, ˌinconˈvincibleness n
ˌinconˈvincibly adv
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014

in•con•vin•ci•ble

(ˌɪn kənˈvɪn sə bəl)

adj.
incapable of being convinced.
[1665–75]
in`con•vin`ci•bil′i•ty, n.
in`con•vin′ci•bly, adv.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
References in periodicals archive ?
In absence of empirical evidence, it is inconvincible that Ghana considered by Ghanaians as the best teach Liberia history in their grade schools.
"I hate to write people off, but if you spend all your time and energy trying to convince the inconvincible you are not going to have time to serve the people who really need you," he added.
It is inconvincible to use the linear model for system identification.
And we can't spend time trying to convince the inconvincible who make up a personality cult of this president who plays on bigotry.
Without possessing knowledge, capacities and teaching abilities, nature of instructors appear to be inconvincible. Teachers are recognized as insightful and competent persons in the learning pyramid.