Gaslighting is different from genuine relationship disagreement, which is both common and important in relationships. Gaslighting is typically effective only when there is an unequal power dynamic or when the gaslighted has shown respect to the gaslighter. Gaslighting involves two parties the 'gaslighter', who persistently puts forth a false narrative, and the 'gaslighted', who struggles to maintain their individual autonomy. Gaslighting is a term used in self-help and amateur psychology to describe a dynamic that can occur in personal relationships (romantic or parental) and in workplace relationships. Oxford University Press named gaslighting as a runner-up in its list of the most popular new words of 2018. The American Dialect Society named gaslight the 'most useful' new word of 2016.

The term has received a number of notable recognitions. Merriam-Webster defines it as ' psychological manipulation' to make someone question their 'perception of reality' leading to 'dependence on the perpetrator'. Largely an obscure or esoteric term until gaining traction in the mid-2010s – The Times only used it nine additional times in the following 20 years – it has broadly seeped into the English lexicon since, and is now used more generally. According to the American Psychological Association in 2021, gaslighting 'once referred to manipulation so extreme as to induce mental illness or to justify commitment of the gaslighted person to a psychiatric institution'. The gerund form gaslighting was first used by the 1950s in The New York Times, it was first used in a 1995 column by Maureen Dowd. 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. 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 alludes to the 1944 American film Gaslight, a remake of the 1940 British film of the same name, which in turn is based on the 1938 thriller play Gas Light. Charles Boyer, Ingrid Bergman, and Joseph Cotten in the film Gaslight (1944)

Gas lighter meaning