'Jì xí' (继媳) is a formal, archaic term meaning 'stepdaughter-in-law' — specifically, a woman who becomes the wife of a man whose previous wife (her predecessor in the same marital role) has died, and who thus enters the same family lineage again. The character 继 (jì) means 'to succeed', 'to continue', or 'to take over', while 媳 (xí) means 'daughter-in-law'. Together, they denote a daughter-in-law who succeeds or replaces another in that role within the same family unit.

This term reflects traditional Chinese kinship structures where remarriage into the same family — especially after widowhood — was occasionally practiced for continuity of lineage or household management. It is rarely used in modern spoken Mandarin and appears mostly in historical texts, legal documents from earlier eras, or scholarly discussions of kinship terminology. Contemporary speakers would typically describe such a relationship circumstantially rather than use this precise term.