adjective. noun. The definition of median is something in the middle or midpoint. When something is scheduled to last for two months, one month is an example of the median timeframe. The median is defined as the middle of a range of values.An example of median is the number 50, which is the middle of the range of the values 1-100.edian-Investment & Finance Definition. The middle number in a series of numbers. To find the median, first arrange the numbers from the smallest to the largest. If the number of items is odd, the median is the number that is in the middle of the series.