median

Etymology

Borrowed from Middle French median, from Latin mediānus (“of or pertaining to the middle”, adjective), from medius (“middle”) (see medium), from Proto-Indo-European *médʰyos (“middle”). Doublet of mean and mizzen. Cognate with Old English midde, middel (“middle”). More at middle.

noun

1. (anatomy, now rare) A central vein or nerve, especially the median vein or median nerve running through the forearm and arm.
2. (geometry) A line segment joining the vertex of triangle to the midpoint of the opposing side.
3. (statistics) A number separating the higher half from the lower half of a data sample, population, or probability distribution. The median of a finite list of numbers can be found by arranging all the observations from lowest value to highest value and picking the middle one (e.g., the median of {3, 3, 5, 9, 11} is 5). If there is an even number of observations, then there is no single middle value; the median is then usually defined to be the mean of the two middle values.
4. (US) The area separating two lanes of opposite-direction traffic; the median strip.
   Seen from street level, the median was clean most days. From the third floor you peered over the benches and trees and saw the trash crowding the subway ventilation grates and paving stones. 2019, Colson Whitehead, The Nickel Boys, Fleet, page 134

adj

1. (anatomy) Situated in a middle, central, or intermediate part, section, or range of (something).
2. (anatomy, botany) In the middle of an organ, structure etc.; towards the median plane of an organ or limb.
3. (statistics) Having the median as its value.