Yep, I have the french version. I found this passage (page 280).
The word I have is "Outrageur". I think it is a demon who says very rude words, who can hurt someone just with words.
At least I guess if we follow the meaning of the word! And Underwood is not that powerful, and this kind of demon must be a minor one, available for Underwood when you read he would never dare to summon a djinn like Barti!! :D
"Je suis Bartim?us!
Je suis Sakhr al-Djinn, N'gorso le tout-puissant, le Serpent ? Plumes d'argent! Je ne me reconnais point de ma?tre. Aussi je te somme ? ton tour, petit.
Qui es-tu pour m'invoquer?"