The word "Opianin" is spelled with the letter "O," followed by "p," "i," "a," "n," "i," and "n." In IPA phonetic transcription, this word would be spelled /oʊpiˈænɪn/. The letter "O" sounds like "oh," "p" sounds like "puh," "i" sounds like "ee," "a" sounds like "a," "n" sounds like "n," and the last "i" sounds like "in." Overall, this word's pronunciation is easy to follow if one is fluent in the IPA phonetic system.