a few various definitions of brainwashing
Mind control (also known as brainwashing, coercive persuasion, mind abuse, thought control, or thought reform) refers to a process in which a group or individual "systematically uses unethically manipulative methods to persuade others to conform to the wishes of the manipulator(s), often to the detriment of the person being manipulated". The term has been applied to any tactic, psychological or otherwise, which can be seen as subverting an individual's sense of control over their own thinking, behavior, emotions or decision making.
Theories of brainwashing and of mind control were originally developed to explain how totalitarian regimes appeared to succeed in systematically indoctrinating prisoners of war through propaganda and torture techniques. These theories were later expanded and modified, by psychologists including Margaret Singer, to explain a wider range of phenomena, especially conversions to new religious movements (NRMs). A third-generation theory proposed by Ben Zablocki focused on the utilization of mind control to retain members of NRMs and cults to convert them to a new religion. The suggestion that NRMs use mind control techniques has resulted in scientific and legal controversy.
The Oxford English Dictionary records its earliest known English-language usage of brainwashing in an article by Edward Hunter in New Leader published on 7 October 1950. During the Korean War, Hunter, who worked at the time both as a journalist and as a U.S. intelligence agent, wrote a series of books and articles on the theme of Chinese brainwashing.
The Chinese term ?? (xi nao, literally "wash brain") was originally used to describe methodologies of coercive persuasion used under the Maoist regime in China, which aimed to transform individuals with a reactionary imperialist mindset into "right-thinking" members of the new Chinese social system. To that end the regime developed techniques that would break down the psychic integrity of the individual with regard to information processing, information retained in the mind and individual values. Chosen techniques included dehumanizing of individuals by keeping them in filth, sleep deprivation, partial sensory deprivation, psychological harassment, inculcation of guilt and group social pressure. The term punned on the Taoist custom of "cleansing/washing the heart" (??, xi xin) prior to conducting certain ceremonies or entering certain holy places.