This noun designates a judge or arbiter—one authorized to render legal decisions or settle disputes. Stephen's speech uses it twice in recounting Moses' history: the Israelite rejecting Moses' intervention asks 'Who made you a ruler and judge over us?' (Acts 7:27), and Stephen notes this same Moses whom they rejected, asking 'Who made you ruler and judge?' (7:35). The doubling emphasizes Israel's pattern of rejecting God's appointed deliverer. The term appears in both questions as paired with 'ruler,' suggesting comprehensive authority over both executive and judicial functions. The usage reflects the ancient Near Eastern fusion of ruling and judging roles.