Impasse
mid 19th century: from French, from im- (expressing negation) + the stem of passer ‘to pass’.
wiktionary
Borrowed from French impasse.
etymonline
impasse (n.)
1763, "blind alley, dead end," from French impasse "impassable road; blind alley; impasse" (18c.), from assimilated form of in- "not, opposite of" (see in- (1)) + passe "a passing," from passer "to pass" (see pass (v.)). Figurative use (c. 1840) is perhaps from its use in whist. Supposedly coined by Voltaire as a euphemism for cul de sac.
... dans l'impasse de St Thomas du Louvre; car j'appelle impasse, Messieurs, ce que vous appelez cul-de-sac: je trouve qu'une rue ne ressemble ni à un cul ni à un sac: je vous prie de vous servir du mot d'impasse, qui est noble, sonore, intelligible, nécessaire, au lieu de celui de cul, ... (etc.) [Voltaire, "A Messieurs Les Parisiens"]
