Or to quote wikipedia again "The "longsword" type exists in a morphological continuum with the medieval knightly sword and the Renaissance-era Zweihänder." There will never be a "perfect" answer.
I'd agree with wikipedia for spatha to arming sword through to claymore, say, but I'd disagree with that Wikipedia quote when it comes to the actual 16th century Zweihanders - those things bear a lot more kinship to military polearms than they do to any traditional swords. The scale is completely different; the use is different also.