There are a few dictionaries on my system,
/usr/share/dict/words /usr/share/dict/american-english /usr/share/dict/british-english /usr/share/dict/ngerman ...
and so on.
How are these files licensed to me? Which project / package provides them?
First you need to determine what package the files belong to. You can use
So, the subject package is
Find the license by clicking the specific package and looking at the copyright over on the right.
(Found this by googling /usr/share/dict/words, and the wikipedia page http://en.wikipedia.org/wiki/Words_(Unix) said it was the wordlist package)
For example, the american-huge wordlist copyright is here: http://changelogs.ubuntu.com/changelogs/pool/main/s/scowl/scowl_6-3/wamerican-huge.copyright