Bellatrix comes from the Latin bellatrix, meaning "female warrior" — the feminine of bellator. The name is also that of the third-brightest star in the constellation Orion (the Amazon Star).
Bellatrix is rising as a girls' name despite its association with the Harry Potter villain Bellatrix Lestrange — parents drawn to the star and the warrior meaning.
Bellatrix reduces to six — the number of warrior grace.