WE'VE BEEN TOTALLY 'X'ed OUT ! ! !
X is also for XERXES, which is the name of a Persian king who lived about 450 years B.C. Being interested in Old Testament History, that was the first name that came to my mind.
But since most people are not too interested in this kind of history I will simply tell you that the most interesting thing he did, other than go to war, was to construct a bridge of boats across the Hellespont in order to invade Greece from Persia. (It's near the Black Sea). There was a narrow strip of sea between the two countries, so he simply lashed his boats together side by side until they formed a bridge over which he could march his armies from one side to the other. Quite a unique idea, I think.
Incidentally, for those of you who think it's not much of a feat to find a word for X, my dictionary has 1089 pages in it and less than one page is devoted to words beginning with X.