How to pronounce "Roterodamus"?

Question

The adjective roterodamus means “of Rotterdam” (the city in Holland). To lovers of Latin, unless they entertain an unusual interest in Dutch geography, the word is familiar probably primarily because of Erasmus of Rotterdam (Erasmus Roterodamus). But how is it pronounced?

I would expect all vowels to be short. The stress would then fall on the antepenultimate syllable, i.e., roteROdamus. In this video, Terence Tunberg, an expert Latin writer whose authority I have no business questioning, certainly stresses it on that syllable. It also sounds quite a bit like he pronounces it with a long o, i.e., roterōdamus.

It is strange, though, that a vowel that does not even occur in the original name of the town should be stressed that way. (The name is in fact stressed on the last syllable in Dutch.)

I have a collection (1) of selected Colloquia by Vives, Cordier and Mosellanus, annotated for use in Latin education, which contains Mosellanus' Dialogus IX, where it says:

[…] hymnos Aurelii Prudentii, gravis et sancti viri, audiemus aut, si hi displiceant, 'Enchiridon militis Christiani' ab Erasmo Roterodámo accuratissime elaboratum.

I take the accent over the a to indicate a non-standard stress on the penultimate syllable (whether all vowels are short or not, we would not expect it there). It was placed there by the editors, the original did not have it. But it makes sense to me.

Which pronunciation is correct?

(1) Lore Wirth-Poelchau, Wolfgang Flurl (ed.): Lateinische Schülergespräche der Humanisten, Bamberg 1992.

Answer 1

A colleague asked me about this a while ago. I agree with that colleague and with you that to native speakers of Dutch it would be absurd (or at least ridiculous) to stress the antepenult.

As for standard rules of stress, it seems to me that it's a bit hard to know (a) which vowels are long or short here and (b) to what extent such rules apply in, let's say, pretty straightforward Latinization of city names in the 15th century.

In all, I'm inclined to consider the pronunciation with the accent on the third syllable hypercorrect, a tendency which appears to be of all times and places indeed. That said, Desiderius noster may have but smiled at such a minor vice (or, better yet, written a hilarious dialogue or letter about it).