In Hebrew, name Leah means – irst wife of Jacob in the Old Testament. Leah became Jacobs first wife by trickery, as Jacob had intended to marry her younger and more beautiful sister, Rachel, who soon became his second and favoured wife. The name Leah originates from the Assyrian language and means ruler.. Other origins for name Leah include – Hebrew, Israeli. Name Leah is most often used as a girl name or female name.