Kurios is the Greek word for lord or master, and it became the Septuagint translators' choice for rendering YHWH into Greek in the third and second centuries BCE. The translators were following the Jewish qere convention of substituting Adonai aloud for the written Tetragrammaton. When they wrote in Greek, they needed a Greek equivalent for the spoken Adonai. They reached for kurios.

Kurios then did work in Greek that adon did not do in Hebrew. In the Roman imperial context into which the LXX was carried, kurios was the standard title for the emperor. By the time the Latin Vulgate rendered kurios as Dominus in the late fourth century, the imperial weight was locked in: Dominus et Deus, "Lord and God," a title claimed by Domitian and inherited by every Roman emperor after him. The Greek word did not hijack God on its own. It handed the translation chain a word that could land either as covenant shorthand or as imperial title, and the political context after Constantine ensured the imperial reading won. The English "Lord" that descends from this chain still carries both weights, even when the reader has forgotten the Hebrew that made the covenant weight possible in the first place.