Meaning "overlapping strips in a window" (to let in air but keep out rain) first recorded 1550s. The form has been influenced by apparently unrelated French Louvre, the name of the palace in Paris, which is said to be so named because its builder, Philip Augustus, intended it as a wolf kennel. Related: Louvered, louvred.
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"]
1690s, "large room or apartment in a palace or great house," from French salon "reception room" (17c.), from Italian salone "large hall," from sala "hall," from a Germanic source (compare Old English sele, Middle English salle, Old Norse salr "hall," Old High German sal "hall, house," German Saal), from Proto-Germanic *salaz.
This is reconstructed to be from a PIE *sel- (1) "human settlement" (source also of Old Church Slavonic selo "courtyard, village," obsolete Polish siolo, Russian selo "village," Lithuanian sala "village."
The sense of "reception room of a Parisian lady" is by 1810 (the woman who hosts one is a salonnière). The meaning "gathering of fashionable people" is by 1888; the meaning "annual exhibition of contemporary paintings and sculpture in Paris" (1875) is from its originally being held in one of the salons of the Louvre, from a secondary sense of the French word, "spacious or elegant apartment for reception of company or artistic exhibitions." Meaning "establishment for hairdressing and beauty care" is by 1913.
"an eating-house, establishment where meals may be bought and eaten," 1821, from French restaurant "a restaurant," originally "food that restores," noun use of present participle of restaurer "to restore or refresh," from Old French restorer (see restore).
In 1765 a man by the name of Boulanger, also known as "Champ d'Oiseaux" or "Chantoiseau," opened a shop near the Louvre (on either the rue des Poulies or the rue Bailleul, depending on which authority one chooses to believe). There he sold what he called restaurants or bouillons restaurants—that is, meat-based consommés intended to "restore" a person's strength. Ever since the Middle Ages the word restaurant had been used to describe any of a variety of rich bouillons made with chicken, beef, roots of one sort or another, onions, herbs, and, according to some recipes, spices, crystallized sugar, toasted bread, barley, butter, and even exotic ingredients such as dried rose petals, Damascus grapes, and amber. In order to entice customers into his shop, Boulanger had inscribed on his window a line from the Gospels: "Venite ad me omnes qui stomacho laboratis et ego vos restaurabo." He was not content simply to serve bouillon, however. He also served leg of lamb in white sauce, thereby infringing the monopoly of the caterers' guild. The guild filed suit, which to everyone's astonishment ended in a judgment in favor of Boulanger. [Jean-Robert Pitte, "The Rise of the Restaurant," in "Food: A Culinary History from Antiquity to the Present," English editor Albert Sonnenfeld, transl. Clarissa Botsford, 1999, Columbia University Press]
Italian spelling ristorante attested in English by 1925. Middle English had similar words in legal language, such as restaurance "restitution." The railroad restaurant car (1872) was one adapted to afford meals to passengers while travelling.