Four-syllable transliteration of 'Mercedes' (Mer-ce-de-s → Mò-xī-dí-sī). The standout literary bearer is Mercédès in 《
基督山伯爵》 (The Count of Monte Cristo) by Dumas - Edmond Dantès's fiancée, who marries his rival when he's imprisoned. The Mercedes-Benz car brand is usually written
梅赛德斯 (Méisàidésī) instead, so seeing
默西迪丝 in a sentence almost always means a person.