Thraldom is the condition of being a thrall — a slave. It names not one act but the whole state of being owned and unfree. You should know up front that this is an old word, and nobody uses it for the modern world. A news report about forced labour today says 'slavery', never 'thraldom'. Where you meet it is in older writing, in history books about medieval Scandinavia and Anglo-Saxon England, in the Bible in older translations, and in hymns and poetry. It carries a heavy, solemn ring, which is exactly why writers used it for figurative slavery: 'the thraldom of sin', 'the thraldom of debt' — a bondage of the soul or the will rather than of the body. Spelling: British writing has both 'thraldom' and 'thralldom'; American writing prefers 'thralldom' with two l's. Both are right, and dictionaries list them together. For your students, the honest advice is: learn to recognise it, do not write it. If you use it in an essay about modern human trafficking, it will read as strange, like wearing a suit of armour to the market.

奴役（的狀態）、為奴之身。是舊時代／文學用語，現代新聞講奴役一律用 slavery；讀古典文學或聖經舊譯本才會遇到。