What is the correct pronunciation of "elytra"?

Solution 1:

Like many concepts, "correct" pronunciation isn't an entirely real thing. One school of thought is that any pronunciation that is widely used without negative repercussions by educated native speakers can be considered "correct".

If you want to know about what pronunciation would be expected based on things like rules, however, it would be /ˈɛlɪtrə/ (which in some accents is automatically replaced with /ˈɛlətrə/), based on the etymology. This situation with this word is somewhat complicated, though, which makes it hard to be too certain about declaring /ˈɛlɪtrə/ the single correct prounciation.

There is a rule that in English words taken from Greek or Latin, stress goes on the syllable that was or would be stressed in Latin.* In the case of elytra, because the y in the second-to-last syllable is short in Greek, the stress in Latin would regularly be placed on the third-to-last syllable. There is a small complication: the consonant cluster tr could optionally be divided between syllables in Greek and Latin, and this would cause the Latin stress to be regularly placed on the second-to-last syllable.

The pronunciation /ɪˈlaɪtrə/ or /əˈlaɪtrə/ would be regular if the Greek word had originally had a long vowel in the second syllable. Since there's no way to know the original length of the vowel without looking up the etymology, /ɪˈlaɪtrə/ or /əˈlaɪtrə/ is a plausible guess based on the spelling for the pronunciation of the word.

The pronunciation /ˈɛlaɪtrə/ is a less plausible guess: not many words have /aɪ/ in an unstressed syllable like this. I wouldn't put much trust in an unsourced Wikipedia pronunciation as evidence for more than a single person's idea about how this word is pronounced.

The pronunciation /ɪˈliːtrə/ or /əˈliːtrə/ does not follow the normal rules of English spelling/pronunciation correspondences; it looks like an attempt to partially apply foreign spelling correspondences. There isn't any particular reason to consider that correct for this word, but there also isn't a clear basis for saying that it is definitely incorrect either.

*However, many words have frequent pronunciations that violate that rule. For example, abdomen is frequently stressed on the first syllable, even though it has stress on the second syllable in Latin; and alveolus is frequently stressed on the second-to-last syllable, even though it is stressed on the third-to-last in Latin.