bijou

Bijou entered French from the Breton bizou (ring, finger ring), from biz (finger). This is one of the rare cases where a Celtic language contributed a word to French that then spread internationally. Breton, a Brittonic Celtic language closely related to Welsh and Cornish, gave French a word for jewelry that Latin apparently could not improve upon.

In French, bijou expanded from meaning a ring to meaning any small, precious ornament. By the seventeenth century, it was used figuratively — a bijou was anything small and perfectly crafted. Bijouterie (the trade of small jewelry, as opposed to joaillerie, the trade of precious gemstone jewelry) became a distinct craft category. French jewelers distinguished between the bijoutier, who worked with gold and enamel in delicate forms, and the joaillier, who set diamonds and rubies. The words encoded a hierarchy of materials.

English borrowed bijou in the seventeenth century. By the nineteenth century, it was used as an adjective meaning 'small and elegant' — a bijou apartment, a bijou cinema. This figurative use is now more common in British English than the literal jewelry meaning. Estate agents in London describe tiny flats as 'bijou' without any awareness that they are calling a one-bedroom apartment a Breton finger ring.

The word's journey — from a Breton word for finger, to a French word for ring, to an English adjective for small — follows a pattern of progressive abstraction. Each language kept the sense of smallness and preciousness but discarded the physical object. The finger disappeared. The ring disappeared. Only 'small and beautiful' remained.