It depends on the context.

In geometry, a median is a line from a vertex of a triangle to
the mid-point of the opposite side.

In statistics, the median of a set of data is the value such
that it is larger than half the values in the data set, and smaller
than a half.
Median means the number that comes up in the middle. An example
would be:

here are your numbers 1,2,3,4,5 your median would be 3. You have
to have your numbers in order before doing median.

If the sequence you are given is not ordered, you must order it
before finding the median. Thus for the sequence 2,1,5,3,4 the
median is 3 (and not 5).
Median means the number that comes up in the middle. An example
would be:

here are your numbers 1,2,3,4,5 your median would be 3. You have
to have your numbers in order before doing median.

If the sequence you are given is not ordered, you must order it
before finding the median. Thus for the sequence 2,1,5,3,4 the
median is 3 (and not 5).