First host of the Dax symbiont, whose personality Kira took on during Jadzia's Trill rite of closure.
Lela Dax was the first Trill joined to the Dax symbiont. In Facets, Jadzia undergoes the zhian'tara, a rite in which the memories of each previous host are temporarily placed in a willing friend, and Kira Nerys accepts Lela.
Meeting Lela, Jadzia recognizes her as the source of many traits that she herself now shows, and the encounter begins the series of conversations with her predecessors that culminates in Jadzia confronting Curzon.