Board game design dictionary
The one I'm aware of is on boardgamegeek.com...
http://www.boardgamegeek.com/wiki/page/Glossary

A similar one for RPGs is on the sister site, RPGGeek.com...
http://www.boardgamegeek.com/wiki/page/RPG_Glossary#
I include this because many of the terms overlap, and especially for dice, are not in the BGG glossary.