What is the meaning of Middlesex? I read somewhere that seax is an old English word meaning a type of Germanic knife, so was the county's original name Middleseax?
I'm looking for the etymology of the word 'Middlesex'.
It's hard to tell without any context, but if you mean Middlesex, with an initial capital letter, then it's a place name, the original one in England. The -sex part is a reference to a group of people called the Saxons, a Germanic tribe that came to England after the Romans left. Apparently some settled in the east (so that location came to be called Essex); some settled in the west (so that location came to be called Wessex). And some settled in between, so their place was called Middlesex. Check here.