tritagonistyoudaoicibaDictYouDict[tritagonist 词源字典]
"The person who is third in importance, after the protagonist and deuteragonist, in an ancient Greek drama", Late 19th century: from Greek tritagōnistēs, from tritos 'third' + agōnistēs 'actor'.[tritagonist etymology, tritagonist origin, 英语词源]