Where can I find a Welsh word list?

I am looking for a Welsh language word list on my Ubuntu system. apt-file search /usr/share/dict/ doesn't show an option. However aspell-cy does exist. The official description is "This package contains all the required files to add support for the Welsh language to the GNU Aspell spell checker." I have installed it but can't find the word list it should be using. Where can I find a Welsh language word list?