"Gaslight" is a psychological thriller film released in 1944, directed by George Cukor. The story revolves around a man who manipulates his wife into doubting her own sanity. He does this by dimming the gas lights in their home and denying that the light has changed when she notices it. The term "gaslighting" has since emerged from the film, referring to a form of emotional abuse where one person makes another question their reality or perceptions. This tactic can be used in various relationships, including romantic partnerships, friendships, and even in workplace dynamics.