Phonetically, it could be de-dra, because the "ae" is pronounced as "e"
Except, in Latin, "ae" is pronounced "i" like in "ice." And in German, a vowel followed by an "e" usually signifies a sort of 'r' sound - it is the long-hand version of what an umlaut is used for. In other words, instead of an umlaut over the "u" in "uber" (just pretend there's an umlaut there, 'cause I can't figure out how to do it), I'd type "ueber." There's a slight "r" noise after the vowel, it is kind of difficult to explain with mere words.
So, imagine, back in Morrowind days, I thought it was pronounced "die-druh"!
I prefer "day-druh" to "dee-druh." The 'ee' reminds me of "nee-ner nee-ner" which is silly and not intimidating.