stepdaughter
n. countablen. the daughter of your husband or wife. You are not her biological parent, but you are married to her parent.
n. the daughter of one's spouse. Refers to a child by marriage rather than by blood.
She is a wonderful stepdaughter to her stepfather.
After the wedding, the two families spent the weekend getting to know each other, including the new stepdaughter.
The legal relationship between a stepdaughter and her stepparent is often formalised through adoption or shared household responsibilities, though it lacks the biological connection of a traditional parent-child bond.
From Middle English stepdoughter, stepdoghter, steopdohter, from Old English stēopdohtor (“stepdaughter”), from Proto-Germanic *steupaduhtēr (“stepdaughter”), equivalent to step- + daughter. Cognate with Saterland Frisian Stäifdochter (“stepdaughter”), West Frisian styfdochter (“stepdaughter”), Dutch stiefdochter (“stepdaughter”), German Low German Steevdochter (“stepdaughter”), German Stieftochter (“stepdaughter”), Danish steddatter (“stepdaughter”), Swedish styvdotter (“stepdaughter”), Icelandic stjúpdóttir (“stepdaughter”).