Merriam-Webster has declared 'gaslighting' as the word of the year for 2022. Merriam-Webster defines 'gaslighting' as a form of mind manipulation that causes a person to question their thoughts or the act of grossly misleading someone, especially for one's advantage. "It was a word looked up frequently every single day of the year," said Peter Sokolowski, Merriam-Webster's editor at large.