The spelling of the word "Orrinthia" is not intuitive, but it can be understood through IPA phonetic transcription. The first syllable is pronounced as "ɔːr," which is represented by the IPA symbol /ɔː/. This is followed by the "rinth" syllable, which can be transcribed as /rɪnθ/. The last syllable "ia" is pronounced as "ia," which is represented as /aɪə/. Therefore, the phonetic spelling of "Orrinthia" is /ɔːrɪnθiaɪə/.