In Emacs, where is ispell's personal dictionary stored?, the documentation http://www.gnu.org/software/emacs/manual/html_node/emacs/Spelling.html says
Your personal dictionary is specified by the variable ispell-personal-dictionary. If that is nil, the spelling program looks for a personal dictionary in a default location.
But where is this default location? In general, how to find out this?
aspell --lang=en dump config
You can setup anaspell.conf
in theetc
directory and then store your personal dictionaries wherever you want.C-h v ispell-personal-dictionary
(as @Lompik said). If that doesn't tell you all you need to know, click the link that takes you to the source code, and see what it uses as the default value.