The word "mesotergum" is a combination of two Greek roots: "meso," meaning middle, and "tergum," meaning back. The correct spelling, as per IPA phonetic transcription, would be /ˌmɛsəʊˈtɜːɡəm/. The first syllable "meso" is pronounced as "meh-so," with the stress on the second syllable. The second part, "tergum," is pronounced as "tur-gum." The word refers to the middle segment of an insect's thorax, which forms part of its exoskeleton.