Rasputin

[ra-spyoo-tin, -tn; Russian ruh-spoo-tyin] /ræˈspyu tɪn, -tn; Russian rʌˈspu tyɪn/
noun
1.
Grigori Efimovich
[gri-gawr-ee i-fee-muh-vich;; Russian gryi-gaw-ryee yi-fyee-muh-vyich] /grɪˈgɔr i ɪˈfi mə vɪtʃ;; Russian gryɪˈgɔ ryi yɪˈfyi mə vyɪtʃ/ (Show IPA), 1871–1916, Siberian peasant monk who was very influential at the court of Czar Nicholas II and Czarina Alexandra.
2.
any person who exercises great but insidious influence.
British Dictionary definitions for grigori rasputin

Rasputin

/ræˈspjuːtɪn; Russian rasˈputin/
noun
1.
Grigori Efimovich (ɡriˈɡɔrij jɪˈfiməvitʃ). ?1871–1916, Siberian peasant monk, notorious for his debauchery, who wielded great influence over Tsarina Alexandra. He was assassinated by a group of Russian noblemen
Word Origin and History for grigori rasputin

Rasputin

acquired name (Russian, literally "debauchee") of Grigory Yefimovich Novykh (c.1872-1916), mystic and faith healer who held sway over court of Nicholas II of Russia. His nickname is from his doctrine of "rebirth through sin," that true holy communion must be preceded by immersion in sin. His name used figuratively in English from 1937 for anyone felt to have an insidious and corrupting influence.