Why is a French fire hydrant called a “bouche”?

A bouche is a mouth, and French hands the word to openings that swallow or deliver something. A fire hydrant is une bouche d’incendie. The steps down to the underground are une bouche de métro. The drain at the kerb is une bouche d’égout, and the vent in a wall is une bouche d’aération. Learn the pattern and the rest of the street labels itself.

The literal mouth is never far away — le bouche-à-oreille is “word of mouth,” passed from one mouth to the next ear. The street compounds are worth banking alongside the plain pavement vocabulary that surrounds them: un trottoir (pavement), un passage piéton (crossing), un lampadaire (streetlight), une plaque d’égout (manhole cover).