Sib and Uncle

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

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

Uncle noun - The brother of your father or mother; the husband of your aunt.

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