An Agnostic dictionary sounds like a good idea, but I don't think the words we use are too different from any other philosophers. I would say, make it a FAQ instead of a dictionary. For example:
- "What does 'Agnostic' mean?"
- "Isn't Agnosticism the same as Athiesm."
- "What does an agnostic think about God?"
- "What does an agnostic think about Science?"
- "Were there any great philosophers who were agnostic?"
- "If I become agnostic, won't I go to hell?"