• WordNet 3.6
    • v unteach cause to disbelieve; teach someone the contrary of what he or she had learned earlier
    • v unteach cause to unlearn "teach somebody to unlearn old habits or methods"
    • ***
Webster's Revised Unabridged Dictionary
    • Unteach To cause to be forgotten; as, to unteach what has been learned.
    • Unteach To cause to forget, or to lose from memory, or to disbelieve what has been taught. "Experience will unteach us.""One breast laid open were a school
      Which would unteach mankind the lust to shine or rule."
    • ***
Chambers's Twentieth Century Dictionary
    • v.t Unteach un-tēch′ to cause to forget, as what has been taught
    • ***


  • H.G. Wells
    “One of the darkest evils of our world is surely the unteachable wildness of the Good.”


Webster's Revised Unabridged Dictionary
1st pref. un-, + teach,


In literature:

But Knappe seemed unteachable by fate.
"A Footnote to History Eight Years of Trouble in Samoa" by Robert Louis Stevenson
It was you who taught me to disdain adulation: will you unteach your pupil?
"The Last Days of Pompeii" by Edward George Bulwer-Lytton
Pericles wiped his forehead, when, impenitent and unteachable, she took the notes in the manner of a cock.
"Vittoria, Complete" by George Meredith
He answered that I was as yet unteachable, being puffed up with the novelty of that heresy.
"The World's Greatest Books, Vol IX." by Edited by Arthur Mee and J.A. Hammerton
Weak and unteachable woman, away with you.
"The Princess Priscilla's Fortnight" by Elizabeth von Arnim
His parables, however, were sometimes used to baffle the unteachable and critical.
"The Life of Jesus of Nazareth" by Rush Rhees
The new Izor said, more than once, that, having taught the fellow to carry the protector, he could not unteach him.
"Nedra" by George Barr McCutcheon
His moral man is as feeble and unteachable as his mental.
"The Memories of Fifty Years" by William H. Sparks
Affairs were made worse by the unteachable folly of the monks of Christ Church.
"The History of England" by T.F. Tout
And it is a bother to begin to unteach you.
"The Farringdons" by Ellen Thorneycroft Fowler

In news:

The unteachable ignorance of the red states.
While speed like his is unteachable, MU commitment Wesley Leftwich (3) is trying to learn the finer points of the receiver position from Hickman aide and former Tiger wideout Marcus James.