A more thorough explanation:

Definition: Consanguineus uterinus refers to a half-sibling who shares the same mother.

Example: John and Jane have the same mother but different fathers. They are consanguineus uterinus.

This term is used in historical contexts to describe the relationship between half-siblings who share the same mother. The prefix "consanguineus" means "blood relative," while "uterinus" refers to the uterus or womb. Therefore, consanguineus uterinus literally means "blood relative by the uterus." This term is important in genealogy and family history research, as it helps to clarify the relationships between family members.