gaslight
The origin of the term is the 1938 British thriller play Gas Light by Patrick Hamilton, which provided the source material for the 1940 British film, Gaslight. The film was then remade in 1944 in America – also as Gaslight – and it is this film which has since become the primary reference point for the term.[4][5][6] Set among London's elite during the Victorian era, it portrays a seemingly genteel husband using lies and manipulation to isolate his heiress wife and persuade her that she is mentally unwell so that he can steal from her. The term "gaslighting" itself is neither in the screenplay nor mentioned in either the films or the play in any context. In the story, the husband secretly dims and brightens the indoor gas-powered lighting but insists his wife is imagining it, making her think she is going insane.
