Quote Originally Posted by An t-Ileach

I've had a thought for some time that maybe there's a much older usage hidden here. Could the 'claymore' be 'mor' with reference to a smaller sword - such as the Roman gladius which acquired widespread use at the end of the Roman Occupation and its descendants carried on a while in Britain. So, could the dirk (biodag) be the 'small sword', as it is traditionally worn in the same way as the gladius - and so the claymore would thus be bigger than it? And so, the two-handed sword would be a mediaeval oddity and not the great sword.
I don't think a dirk would ever have been considered a "sword." The Scottish dirk as we know it evolved from the common European ballock-dagger between ca. 1590 and ca. 1650, and initially had a blade length only in the 10-12 inch range. Such a knife is hardly a "sword." Longer bladed dirks made from cut-down sword blades was a later development.

Finally, the two-handed great sword was always a "specialty" sword, being wielded by big strong guys who could handle them, usually for the purpose of breaking opposing pike staffs....