I remembered Graham's other compound word that I couldn't recall when writing last month's "On Language" post. Actually, Graham said it again this morning, and I thought, "That's it!!!"
The word is goodea, good + idea. As in, "I have a goodea!" Graham says this often, brightly, and confidently, but never with any elaboration. For example:
Graham: I have a goodea!
Me: You do? You have a good idea?
Graham: (nods heartily)
Me: What's your good idea?
Graham: (blank-stare pause... then) I have a goodea!