French expressions with no comparable English terms

Adieu – “farewell” when you don’t expect to see the person again until you are in heaven
Agent provocateur – person who attempts to provoke individuals or groups into committing unlawful acts
Attentat – assassination attempt, terrorist attack, bombing
Au fait – to be conversant with, or informed about
Avant-garde – innovative, especially in the arts
Bête noir – something that is particularly distasteful or difficult and to be avoided
Cinéma vérité– unbiased, realistic documentary film-making
Coup d'etat - overthrow of government
Defrisher - to lay the groundwork
Déjà vu – phenomenon of feeling you have already seen or done something when you’re sure you haven’t
Demimonde – marginal or disrespectful group; prostitutes and/or kept women
De rigueur – socially or culturally obligatory
Dernier cri – Newest fashion or trend
En blanc – entire membership of court is in session
Enfant terrible – troublesome or embarrassing person in a group
Faux pas – something that should not be done; a foolish mistake
Folie à deux – mental disorder which occurs simultaneously in two people with a close relationship or association
Force majeure - superior or greater force
Hypercultivé – extremely learned
Je ne sais quoi – used to indicate “a certain something”
Joie de vivre – quality in people who live life to the fullest
Matineé– first showing of movie or film; or midday romp with one’s lover
Risqué – suggestive, overly provocative
Roman-fleuve – long multi-volume novel
Savoir faire – synonymous with tact or social grace
Soi-disant – what one claims to know about oneself, so-called or alleged
Touché – “you got me”
Trompe l’oeil – painting which tricks the eye into believing it is real; also refers, in general, to artifice and trickery