unsay

To retract (something said).

To recant or recall after having been said; retract; take back: as, to unsay one’s words.

To recant or recall, as what has been said; to refract; to take back again; to make as if not said.

To withdraw, retract (something said).

To not have said (since this is physically impossible usually in the subjunctive, as I wish I could unsay).

take back what one has said