A Matriarch is significant female within a family or group, sometimes taking a leadership role or holding some cultural significance within the group.
In the Pa'haquel species, the wife of the Clan elder served as Clan matriarch. If the Elder was unmarried, the position fell to the most senior female member of the Clan Elder's line. In 2380, the matriarch of Clan Qui'Tir'leg was Qui'chiri. The duties of the matriarch included preparing newly killed star-jellies for habitation. Deanna Troi told Qui'chiri that she considered the position of first officer to be comparable to that of matriarch. (TTN novel: Orion's Hounds)