Origins
The word 'salon,' meaning a reception room, a gathering of intellectuals, or a beauty establishment, entered English in the 1690s from French 'salon' (a large room, a drawing room), from Italian 'salone' (a large hall), the augmentative of 'sala' (hall, large room). The Italian word descends from Lombard or Frankish *sal (hall, house), from Proto-Germanic *salą (dwelling, hall), making 'salon' one of those words that traveled from Germanic through Italian and French before returning to a Germanic language — English — in a form its originators would not have recognized.
The Proto-Germanic root *salą has left traces throughout the European languages. In English, it may be related to 'hall' itself (though this derivation is debated). In Old Norse, 'salr' meant 'hall,' and appears in one of the most famous compound words in Norse mythology: 'Valhöll' (Valhalla), the 'hall of the slain' where warriors chosen by the Valkyries feasted with Odin after death. The French 'salle' (room, hall) comes from the same Germanic source, as does the Spanish 'sala' and the Portuguese 'sala.' The Germanic peoples who settled across the former Roman Empire brought their word for 'hall' with them, and it took root in every Romance language.
The intellectual 'salon' — a regular gathering of writers, artists, philosophers, and other cultivated persons in the private home of a prominent host — is one of the most distinctive cultural institutions of European history. The tradition began in seventeenth-century Paris, most notably in the salon of the Marquise de Rambouillet, who hosted literary and intellectual discussions in her 'chambre bleue' from around 1607. The great salons of the eighteenth century — hosted by Madame de Geoffrin, Madame du Deffand, Mademoiselle de Lespinasse, and others — were crucibles of Enlightenment thought, places where Voltaire, Diderot, d'Alembert, and Rousseau refined their ideas in conversation.
Latin Roots
The salon tradition is significant for linguistic history because it placed enormous value on the quality of conversation. The French ideal of 'esprit' (wit) and the English concept of 'politeness' (both words, interestingly, derived from polishing: 'esprit' from Latin 'spiritus,' breath/spirit, but refined in salon culture, and 'polite' from Latin 'polire,' to polish) were cultivated and enforced in salon settings. Words were tested, refined, and either adopted or rejected by the salon's collective judgment. The salons thus functioned as informal language academies, shaping the development of French prose style.
The beauty 'salon' — the sense most common in modern American English — emerged in the nineteenth century as an elevation of the simpler 'shop.' A 'hair salon' sounds more refined than a 'barber shop,' and the word was deliberately borrowed from its intellectual associations to lend an air of sophistication to commercial grooming. The French spelling and pronunciation reinforce this aspirational quality: calling a business a 'salon' rather than a 'shop' positions it as a place of cultivation and taste.
The word's triple life in English — as a room, a cultural institution, and a commercial establishment — reflects the three stages of its semantic journey: from the physical space of the hall, through the social practice that the hall enabled, to the commercial appropriation of the social prestige that the practice conferred.