Final answer:
Cross-cousins are offspring of a father's sister and a mother's brother in a bilateral cross-cousin marriage system.
Step-by-step explanation:
Cross-cousins are offspring (children) of a father's sister and a mother's brother. They are considered as cousins from different lines of descent, since one is related through the father's side and the other through the mother's side. This is known as a bilateral cross-cousin marriage system, which is practiced in certain societies.
Learn more about Cross-cousins