You made a joke with stick, but actually, I think that might be a good guess.
I don't see any realistic connection with stick. Can you sell it to me?
There's the halo you sometimes see round the moon (ice crystals I think?) >> 'scientist'.
And I can almost picture the word "Halo" in my wife's CD collection, as a group or album name or something >> 'rock'. I wonder why Galz thought their team should avoid rock? Is there a rock group called "Firewall" or something?
But mostly I think I'm happiest with 'cap'. Unless Didds is hoping we'll rule it out based on the conversation about it maybe being one of red's words for construction? Would have been helpful if Eevee and Galz could have guessed that one.
I'm assuming no googling actually means no research in general. It should be like we're actually sitting round a table playing a game. We know what we know and that's it. No getting up and looking in reference books, no phone-a-friend, no going and looking through my wife's CD collection.