unteach

verb2

1. •
   To cause (someone) to unlearn; to make (someone) forget something they have been taught, or recognize it as erroneous, etc.
2. •
   To cause (something previously learned) to be forgotten, or recognized as an error, etc.

   • "I did say that the mass was the Romish name for the sacrament." Upon which the rector "beat his head like a man distracted;" and declared that he should into the school and unteach that also. — 1859