'Mean' is a no mean word.

This is why people like to use it as a means to convey so many meanings, even the 'meaning' proper.

A mean cook can be a mean creature, which means his character is widely diverged from the mean value of the statistical distribution, but meanwhile, a mean cook must be an absolutely no mean cook, which means he cooks no mean dishes.

If you are confused, feel free to ask -- 'What you mean?'

Is the inventor of this mean word a mean man or a mean man or a mean man? I'm not sure. This is a mean question. The only thing I'm sure of is that he must be really mean with his lexicon.