In
colloquial language
average usually means the sum of a list of numbers divided by the size of the list, in other words the
arithmetic mean. However it can alternatively mean the
median, the mode, or some other central or typical value. In statistics, these are all known as
measures of central tendency. The concept of an average can be extended in various ways in mathematics, but in those contexts it is usually referred to as a
mean (for example the mean of a function)