The word "enthralldom" may not be a commonly used term, but there are several synonyms that convey a similar meaning. One such synonym is "captivity" which implies being held captive or enslaved. Another synonym is "bondage" which connotes the condition of being bound or restrained by something or someone. Yet another is "domination" which suggests being controlled or oppressed by a more powerful entity. And finally, "subjugation" implies being subordinated or put under the control of another. All these synonyms share the sense of being held against one's will or being under the control of another.