No, Average is any measure of central tendency, which include all of the median, mode, and the various means (harmonic, geometric, arithmetic,...), as well as some others.
The mode is the most broadly applicable, since (at least if you accept multiple values) it is well-defined on any, even merely categorical, data. The median requires ordinal data, and the various means tend to require at least interval-level measures (some of them require ratio-level measures.)
The arithmetic mean seems to be the most common grade school mathematics “average”, possibly because its the one that does the most to exercise basic arithmetic skills. But its rarely, when distinct from the median and mode, the most useful, and often doesn’t match the intuitive understanding of “average”.
> In descriptive statistics, the mean may be confused with the median, mode or mid-range, as any of these may be called an "average" (more formally, a measure of central tendency). The mean of a set of observations is the arithmetic average of the values...
The mean is what is often meant by the term but not always. "How to lie with statistics" is a great book and I highly recommend it to anyone still confused by such terms -- or anyone who ever sees, say, ads.
"There are three kinds of lies: Lies, damn lies and statistics" -- Mark Twain