milieu

Milieu comes from French milieu, meaning a physical or social environment, from Middle French milieu/meilleu/mileu, from Old French milliu/meillieu/mileu meaning 'middle.' That Old French word was built from mi- ('half,' from Latin medius) plus lieu ('place,' from Latin locus).

The word started as a literal description of the middle point of a place, and over time it shifted from marking a spot in space to naming the surrounding environment or social group someone belongs to.

It shares its second half with English 'lieu,' as in 'in lieu of,' both tracing back to Latin locus, meaning 'place.'