Fifth House of Betazed

From Memory Alpha, the free Star Trek reference

The Fifth House of Betazed is one of the houses of the planet Betazed.

Lwaxana Troi is daughter of the Fifth House, in addition to being heir to the Holy Rings of Betazed and the holder of the Sacred Chalice of Rixx. (TNG: "Haven", "Half a Life", DS9: "The Forsaken")