Webster's Revised Unabridged Dictionary · 1913

Unlearn

Unlearn , transitive verb

[1st pref. un- + learn.]

1.
To forget, as what has been learned; to lose from memory; also, to learn the contrary of.
I had learned nothing right; I had to unlearn everything. — Milner
2.
To fail to learn. [Obsolete] — Dr. H. More