ETYM Latin medianus, from medius middle. Related to Medial.
1. Relating to or situated in or extending toward the middle; SYN. medial.
2. (Statistics) Relating to or constituting the middle value of an ordered set of values (or the average of the middle two in an even-numbered set); SYN. average.

1. A medial part (as a vein or nerve)
2. A value in an ordered set of values below and above which there is an equal number of values or which is the arithmetic mean of the two middle values if there is no one middle number; a vertical line that divides the histogram of a frequency distribution into two parts of equal area; a value of a random variable for which all greater values make the cumulative distribution function greater than one half and all lesser values make it less than one half
3. A line from a vertex of a triangle to the midpoint of the opposite side; a line joining the midpoints of the nonparallel sides of a trapezoid
4. Median strip
5. The value below which 50% of the cases fall.
6. In mathematics and statistics, the middle number of an ordered group of numbers. If there is no middle number (because there is an even number of terms), the median is the mean (average) of the two middle numbers. For example, the median of the group 2, 3, 7, 11, 12 is 7; that of 3, 4, 7, 9, 11, 13 is 8 (the average of 7 and 9).
In geometry, the term refers to a line from the vertex of a triangle to the midpoint of the opposite side.