referee

From the past participle of Old French referer ("to relate, to refer"), itself from Latin referre ("to carry back, to report, to notify"). English shaped it as if from refer plus the suffix -ee, marking the person to whom something is referred for consideration.

Because -ee marks the receiver of an action, the word settled onto the person handed the job of deciding — the one disputes are referred to.

It shares its root with refer, the two words growing from the same Latin referre, one naming the act, the other the person on the receiving end of it.