Shì yì is a formal, literary noun meaning 'generational descendants' — those who inherit lineage across multiple generations. The character shì (世) means 'generation', 'age', or 'world', and often denotes a span of time or familial succession; yì (裔) means 'descendant', 'offspring', or 'lineal heir', historically used in classical texts to refer to bloodline continuity. Together, shì yì emphasizes deep ancestral continuity — not just immediate children, but descendants across centuries.

This term appears most frequently in historical, genealogical, or ceremonial contexts: official records of noble families, conservation documents about endangered species with documented lineages, or scholarly discussions of cultural inheritance. It carries solemn, respectful connotations and is rarely used in casual speech. While it can apply to human lineages, it’s also employed in zoology and ecology when tracing hereditary traits or breeding lines — especially for rare or protected animals whose pedigree is carefully preserved.