'Gaslighting' has been named the word of 2022 by dictionary Merriam-Webster after a 1,740 per cent surge in searches for the expression on its website in a year.

There was not a single event which drove spikes in the curiosity of searchers for the term, which usually happens when there is a new word of the year. Merriam Webster defines gaslighting as the psychological manipulation of a person, usually over an extended period of time.

Gaslighting causes the victim to question the validity of their own thoughts, perception of reality, or memories and typically leads to confusion, loss of confidence and self-esteem, uncertainty of one's emotional or mental stability, and a dependency on the perpetrator.

It is a tool usually used by abusers in relationships and by politicians and other newsmakers. Gaslighting can happen between romantic partners, within a broader family unit and also among friends.

People can gaslight as a corporate tactic or a way to mislead the public. There is also medical gaslighting, when a health care professional dismisses a patient's illness or symptoms as 'all in your head.' 

The word first appeared in 1938, despite its recent prominence and being used in 'Gaslighter' The Chicks 2020 album. Its use in 1938 was for a play called 'Gas Light' by Patrick Hamilton. 

In the 1940s, there were two film adaptations of the play. There was one in 1944 by George Cukor called Gaslight, starring Ingrid Bergman as Paula Alquist and Charles Boyer as Gregory Anton.