Xaire likely draws from Greek chaire, meaning 'rejoice' or 'be glad,' used as a greeting in classical Greek.
Xaire is the direct anglicization of the ancient Greek word χαῖρε (khaîre), the singular imperative of the verb χαίρω — "to rejoice, to be glad, to flourish." It functioned as the standard greeting and farewell in Classical Greek, the ancient equivalent of both "hello" and "goodbye," wishing the person you addressed a life of joy. When the Archangel Gabriel greets Mary in the Gospel of Luke — "Χαῖρε, κεχαριτωμένη," often translated "Hail, full of grace" — the word carries its full weight of blessing.
The Neo-Latin and ecclesiastical tradition passed this salutation into liturgical use across centuries, making it one of the most freighted single words in Western spiritual history. As a given name, Xaire is exceedingly rare in any era — it is more a living fragment of language than a settled name, which is precisely what gives it its charge. To name a child Xaire is to give them a word that means "rejoice" and has meant it for three thousand years: a name that is also a daily incantation of wellbeing.
The X opening — uncommon in English, drawn straight from the Greek chi — lends it visual distinctiveness and a slight otherworldly quality, while the pronunciation (closer to "ZAY-ray" or "HAIR-ay" depending on the tradition) rewards anyone who takes the trouble to learn it. It is a name for parents who love language itself, who want their child's identity rooted in something older and larger than the current moment.