Matriarchy is a social system in which positions of dominance and authority are primarily held by women. In a broader sense it can also extend to moral authority, social privilege, and control of property. While those definitions apply in general English, definitions specific to anthropology and feminism differ in some respects. Most anthropologists hold that there are no known societies that are unambiguously matriarchal.

Matriarchies may also be confused with matrilineal, matrilocal, and matrifocal societies. While some may consider any non-patriarchal system to be matriarchal, most academics exclude those systems from matriarchies as strictly defined.

Source: Wikipedia

The matrilineal Khasi society in northeastern India is one of the few surviving female-dominated societies in the world, comprising 800,000 people. Following custom, the youngest daughter inherits the property and after marriage her husband movies into the family house. The system prevents cross-marriages between clans, which is taboo is Khasi society, and could lead to genetic inbreeding. Nontribals are increasing marrying into the tribe (some say for its property), whilst Khasi women say they prefer to marry outsiders because their own tribesmen tend to be irresponsible in family matters. The result is that many Khasi men have become paupers and very few of the 2,000 Khasi clans are pure-bred Khasis.
(F) Fuzzy exceptional problems