The word "tonnagium" is a tricky word to spell. Its IPA phonetic transcription is /tɒnˈeɪdʒiəm/. The "tonna" syllable is spelled with two "n's" because it comes from the Latin word "tonna" meaning "tunable." The "gi" combination in "giu" represents the sounds /dʒə/ or /dʒu/. The "-ium" suffix is a common suffix in Latin, indicating a metallic element. Therefore, "tonnagium" refers to a tunable metallic element. Despite its complex spelling, this word has an interesting historic significance in the field of chemistry.