‘曾祖’ (zēngzǔ) means ‘great-grandfather’ — the father of one’s grandfather or grandmother. It is a compound noun formed from two characters: ‘曾’ (zēng), which here indicates a generational remove of two steps back (i.e., ‘great-’), and ‘祖’ (zǔ), meaning ‘ancestor’ or ‘grandparent’. Unlike English, where ‘great-’ can be repeated (e.g., great-great-grandfather), Chinese uses specific terms for each generation: 曾祖 (great-grandfather), 高祖 (great-great-grandfather), etc.

This term is used in formal family contexts, genealogical discussions, or respectful speech about elders. It carries a tone of reverence and is common in written records, family trees, and traditional ceremonies. While rarely used in casual daily conversation among young people, it appears frequently in historical narratives, ancestral worship contexts, and official documents related to lineage.