untaught

(verb) cause to disbelieve; teach someone the contrary of what he or she had learned earlier. Synonyms: unteach.

(verb) cause to unlearn. Synonyms: unteach. Example: "Teach somebody to unlearn old habits or methods."

(adj) lacking in schooling. Synonyms: unschooled, untutored. Examples: "Untaught people whose verbal skills are grossly deficient." "An untutored genius." "Uneducated children."