Sib and Stepparent

Sib noun - One related by blood or origin; especially on sharing an ancestor with another.

Stepparent and sib are semantically related in relative topic. In some cases you can use "Stepparent" instead a noun "Sib", when it comes to topics like member of a family.

Stepparent noun - The spouse of your parent by a subsequent marriage.

Sib and stepparent are semantically related in relative topic. You can use "Sib" instead a noun "Stepparent", if it concerns topics such as member of a family.