'Gaslighting' is Merriam-Webster's 'word of the year.' Here's why [wnd.com]
The term derives from the classic 1944 film “Gaslight,” in which an extraordinarily evil criminal, who has recently gotten married, psychologically manipulates his perfectly sane wife into believing she’s going insane as a means of distracting her from uncovering his horrendous crime spree. From the movie emerged the modern psychological term “gaslighting,” which means, “to cause (a person) to doubt his or her sanity through the use of psychological manipulation.”