Arbiter
From Textus Receptus
The word appears in the NIV in Luke 12:14 Jesus replied, "Man, who appointed me a judge or an arbiter between you?"
The ESV has it in Job 9:33 There is no arbiter between us, who might lay his hand on us both.
The World English Bible has it in Isaiah 29:21 who cause a person to be indicted by a word, and lay a snare for the arbiter in the gate, and who deprive the innocent of justice with false testimony.