means The middle value in a sorted set of numbers — the point where half fall below and half above — or, on a road, the strip dividing opposing traffic.

from From the Latin 'medianus,' meaning 'in the middle,' built on 'medius' ('middle') — the same family that gives us 'median,' 'medium,' 'mediate,' and even 'mediterranean' (the sea 'in the middle of the land'). It entered English by way of mathematics and geometry, then later spread out onto highways to name that calm middle strip keeping the lanes apart.