A modern form influenced by the French word deja, giving it a stylish, already-familiar feel.
Dejah owes its place in naming consciousness largely to one of science fiction's most enduring heroines: Dejah Thoris, the Princess of Helium and central figure of Edgar Rice Burroughs' Barsoom series, beginning with A Princess of Mars in 1912. In Burroughs' imagined Martian civilization, Dejah Thoris is not merely a love interest but a scientist, a diplomat, and a warrior of fierce intelligence — a proto-feminist figure hidden inside what appeared on the surface to be pulp adventure. Her name, invented whole by Burroughs, has an exotic, melodic quality that has made it perennially appealing.
Outside the Barsoom universe, Dejah functions in English-speaking communities as a feminine name in its own right, related to but distinct from Deja — which itself derives from the French déjà, as in déjà vu, suggesting memory, familiarity, and the uncanny sense of recognition. The layering of these associations — the warrior princess, the French sensation of having been here before — gives the name a dreamlike, slightly otherworldly quality. In African-American communities particularly, Dejah has been embraced as a name that is feminine and striking without adhering to European conventions.
The 2012 film John Carter brought Dejah Thoris to a new generation of viewers, played by Lynn Collins, introducing the name to families who might never have opened a Burroughs novel. Today it stands as an example of how fiction permanently expands the vocabulary of naming.