The word "monopolium" is not a commonly used word in English. However, its spelling can be explained using the International Phonetic Alphabet (IPA). The first syllable, "mo," is pronounced as /moʊ/ while the second syllable, "nop," is pronounced as /nɑp/. The final syllable, "lium," is pronounced as /liəm/. Therefore, the correct spelling of the word "monopolium" is: /moʊ.nɑp.liəm/. In some cases, the spelling may also be written as "monopolyum," using the same pronunciation.