OK I'm now filling small gaps in the vast Geezer knowledge! With my tea this morning I scoffed a couple of Ginger nuts and I was wondering why are Ginger Biscuits called "Nuts"? An important question I'm sure you agree!
As long ago as the 1700s, they were called 'gingerbread nuts'. The 'nut' idea came from the fact that they were small - smaller than today, I guess - button-shaped and hard. That, combined with their brownish colour, made them seem nut-like, I daresay.