chaise

Chaise is French for 'chair,' but it arrived in English through a specific mispronunciation. In standard Old French, the word was chaire (from Latin cathedra, 'seat'). Parisian French, however, underwent a sound change in the fifteenth and sixteenth centuries in which /r/ between vowels became /z/. Chaire became chaise in Parisian speech. The change was so widespread that chaise replaced chaire as the standard French word for chair.

English borrowed both forms. 'Chair' came from the older chaire in the thirteenth century. 'Chaise' came from the Parisian pronunciation in the seventeenth century, but English treated it as a different word with a different meaning. A chair was for sitting upright. A chaise was for reclining. The chaise longue — literally 'long chair' — became the specific form that English speakers associated with the word.

Americans frequently mangle 'chaise longue' into 'chaise lounge,' treating longue as though it were the English word 'lounge.' The error is so widespread that 'chaise lounge' now appears in American dictionaries as an accepted variant. A mispronunciation of a mispronunciation. The word has been mangled twice, and both times the error stuck.

The chaise longue as a piece of furniture was popularized in France during the reign of Louis XV, when Madame de Pompadour and other court figures reclined on them in portraits. The form — a chair with an extended seat for the legs — was designed for women in corsets who could not bend at the waist comfortably. The furniture solved a problem created by other furniture: restrictive clothing.