Longman Dictionary of Contemporary English
ineducable
adjective
EXAMPLES FROM CORPUS
▪ It provides special education, as noted in Chapter 4, for educationally subnormal children and for those previously described as ineducable.
▪ These are the 3% placed in welfare institutions or left at home with parents, classed as ineducable.
Douglas Harper's Etymology Dictionary
Wiktionary
ineducable
a. Incapable of being educated