Definition - What does Stepchild mean?
A stepchild is a child whose biological parent marries someone who is not the child's other biological parent. This could be after a divorce occurs between the two biological parents of the child.
Laws regarding custody, rights and privileges of stepchildren vary from state to state.
Justipedia explains Stepchild
Stepparents are not the official legal guardians of stepchildren unless they formally adopt them. If they do adopt them, then the stepchildren have all of the rights and privileges that they would if they were the person's biological children. Whether or not a stepchild has been formally adopted can also play a role in things such as inheritance and other transfers of family property.
It is possible for a stepchild to have more than one stepparent if both biological parents marry other people.