Dalanni appears to be a modern invented name, likely built from contemporary prefix-and-suffix styling.
Dalanni is a name that sits at the intersection of creative modern coinage and possible Celtic heritage, most plausibly emerging from the Irish surname Ó Dálaigh and its anglicized form Delaney, which carries the meaning "dark challenger" or "descendant of the competitor." In the Irish tradition, Dálaigh was a bardic family of considerable prestige, producing generations of poets and scholars who served the Gaelic nobility.
The feminization and elongation into Dalanni softens the surname's competitive edge into something lyrical and flowing. As a given name, Dalanni appears most frequently in the contemporary United States, reflecting the broader American tradition of transforming surnames and place names into novel first names and of reimagining older roots with fresh phonetic shapes. The doubled "n" and the soft trailing vowel give it a musical cadence that connects it aesthetically to names like Savannah or Giovanna without directly borrowing their etymology.
What makes Dalanni culturally compelling is precisely its hybrid nature — it honors the long tradition of names built on ancestral identity (the "Dal-" root suggesting lineage and tribe) while embracing the modern impulse toward individuality and sonic beauty. Parents drawn to it often describe responding to its warmth and rhythm before researching its roots, a pattern common to names that succeed on pure sound and then reveal rich history upon closer examination.