Stepchild
A stepchild is the offspring of one's spouse, but not one's own offspring, either biologically or through adoption. Perception. The traditional usage of the term "stepfamily" refers to a married couple where one or both members of the couple have children, with a different biological parent. Some also apply the term loosely to non-custodial relationships where “stepparent" can refer to the partner of a parent with whom the child does not live.