It's all Welsh to me

Had a med student trail me around for a few hours this evening.  He seemed like a decent guy, in that he was interested in discussing things other than medicine.  As a result, when he asked me to sign his "attendance book" (to prove that he bothered to turn up, a program probably instigated as a direct result of students like me who took the university's unofficial slogan of "Teach Yourself Medicine" rather too literally), I wrote some feedback in there to the effect that I thought his pronunciation was excellent and that I appreciated his willingness to contribute anecdotes from his extensive and esoteric background knowledge.

We had this strange conversation where somehow he ended up explaining the etymology of the word "dysdiadokinesia" to me.  Because it relates to Alexander the Great and his successors, I ended up talking to him about Ptolemy, and because that sounds vaguely like Potomac we ended up talking about the American civil war and Washington crossing the Delaware river.

Interestingly, when I got home I attempted to verify the etymology of dysdiadokinesia and found it less easy than I expected.  I ended up trying to use Google Translate to translate the word "diadochos" from Greek into English, but Google insisted that "diadochos" is actually Welsh.  Welsh for "diadochos" in fact.  However did we live before Google?

So then I tried translating "diadochos" from Welsh into Greek, and got "Διάδοχος", which I then translated back into English and got "successor".  The Diadochi were indeed the Macedonian successors of Alexander the Great, like Ptolemy (who ruled in Egypt).

But I'm still not so clear on what that has to do with dysdiadokinesia.  Oh well.