gaslighting

Slang for abusive behavior, specifically when an abuser manipulates information in such a way as to make a victim question his or her sanity. It's a form of persistent manipulation that causes the victim to doubt him or herself and ultimately lose his or her own sense of identity and self-worth. It should be noted that gaslighting can occur in personal relationships, at the workplace, and even over an entire society.

Historical perspective: The term originated from the 1938 play Gas Light (known in the United States as Angel Street) by Patrick Hamilton and two film adaptations (1940 and 1944), both named Gaslight, about a woman whose husband slowly manipulates her into believing she is going insane.