"Gaslighting" is Merriam-Webster dictionary's 2022 word of the year.
A driver of disorientation and mistrust, gaslighting is "the act or practice of grossly misleading someone especially for one's own advantage." 2022 saw a 1740% increase in lookups for gaslighting, with high interest throughout the year.
Its origins are colorful: the term comes from the title of a 1938 play and the movie based on that play, the plot of which involves a man attempting to make his wife believe that she is going insane. His mysterious activities in the attic cause the house's gas lights to dim, but he insists to his wife that the lights are not dimming and that she can't trust her own perceptions.
Gaslighting originally (and properly) refers to a betrayal of familial trust, not jocular clickbait or when politicians bullshit on social media. But now it also encompasses other things we implicitly trust, such as those—or even just "lies" in general.
in recent years, we have seen the meaning of gaslighting refer also to something simpler and broader: "the act or practice of grossly misleading someone, especially for a personal advantage." In this use, the word is at home with other terms relating to modern forms of deception and manipulation, such as fake news, deepfake, and artificial intelligence.