The spelling of the word "XINSUM" may seem confusing at first, but it can be easily broken down using the International Phonetic Alphabet (IPA). The first two letters, "XI," are pronounced as /zʌ/ (rhyming with "duh"). The next three letters, "NSU," are pronounced as /ɛnsju/ (rhyming with "fenshoo"). Finally, the letter "M" at the end is pronounced as /ɛm/ (rhyming with "gem"). So, the complete pronunciation of "XINSUM" is /zʌɛnsjuɛm/.