"surroundings," 1877, from French milieu, "middle, medium, mean," literally "middle place" (12c.), from mi "middle" (from Latin medius; see medial (adj.)) + lieu "place" (see lieu).
milieu mi·lieu (mĭl-yu', mēl-yɶ')n. pl. mi·lieus or mi·lieux (-lyɶ')
The totality of one's surroundings; an environment.
The social setting of a mental patient.