"Omnipotent" is stressed like omˈnipotent, with a stress on second syllable. But both components are stressed on the first syllable ('omni and 'potent). And a comparable word, "omnipresent", has the stress on the third syllable (and secondarily on the first).
Why does the stress of "omnipotent" go against that of "omni", "potent", and "omnipresent"?
Best Answer
It is very frequent, at least in BrE, that long Latin/Greek words are stressed on the third-last syllable. In phonetics there are special terms for the syllables.
the ultimate syllable is the last one
the penultimate is the second-last one
the propenultimate is the third last one.
These terms are very academic and not appropriate for quick notation. (In my notes I write: stress on 3m meaning on syllable 3 minus, the third-last one.)
I'll try to find sth on the Internet about words with stress on the third-last one and whether one can formulate a general rule.
After looking around a bit I have the feeling such an article has to be written yet.