From Longman Dictionary of Contemporary EnglishSvengaliSven‧ga‧li /svenˈɡɑːli/ noun [countable] ROa man who has the power to control people’s minds and make them do bad or immoral things
Examples from the Corpus
Svengali• Firstly by the theatre; secondly by what he called his Pygmalion, even his Svengali, complex.Origin Svengali (1900-2000) Svengali, character who uses hypnotism to get control over people in the book Trilby (1894) by George Du Maurier 