Final answer:
The karanavan was the oldest male member of the Nayar joint family in Kerala, India, who acted as the head and had various responsibilities including managing finances, property, and legal affairs.
Step-by-step explanation:
The karanavan was a position of authority and responsibility within the Nayar community in Kerala, India. The karanavan was the oldest male member of the family, usually the father or the eldest surviving male, who acted as the head of the joint family. They played a crucial role in managing the family's finances, property, and legal affairs. The karanavan also had the authority to make decisions regarding marriage, inheritance, and other important matters within the family.