hold forth

３０年位前に買ったまま読んでいない本が出てきたので、読むことにしました。 Artificial Intelligence by Lawrence Stevensですが、余りAIのレベルが大した事がなかった頃の本なので読む価値も余りないとも思われますが、図書館から借りて読む本の合間に読むことにします。
The literary and oral traditions of automata are rich. Back in the Middle Ages, for example, Pope Syslvester II claimed to have a forturne-telling robot that would respond with "yes" or "no" when asked questions. Also in the Middle Ages, a group of Arab astrologers claimed to have created a thinking machine called the Zairja, which could hold forth on philosophical subjects.
熟語 "hold forth" の意味が分からないので辞書を引きます。
・Oxford English Dictionary: Talk lengthily, assertively, or tediously about a subject.: he was holding forth on the merits of the band's debut album
・Collins Dictionary: to speak for a long time or in public: He was still holding forth about the family's tendency to high cholesterol when something moved just beyond the French windows.
・Cambridge English Dictionary: to talk about a particular subject for a long time, often in a way that other people find boring: She held forth all afternoon about/on government incompetence.
これは覚えて置きたい熟語ですね。