To take from an electronically controlled machine its stored-up information; to erase a computer's programming. (1960)
To affect one's mind by using extreme mental pressure or any other mind effecting process. (i.e. hypnosis)
If you brainwash someone, you force them to believe something by continually telling them that it is true, and preventing them from thinking about it properly. They brainwash people into giving up all their money We were brainwashed to believe we were all equal. to make someone believe something that is not true, by using force, confusing them, or continuously repeating it over a long period of time