-ator +

To arbitrate means to hear both sides of a dispute and then to make a decision; while an arbitrator acts like a judge and determines which side is right.

Someone; usually a man, who navigates in outer space either in interplanetary travel or in interstellar travel.

A person who performs auscultation; that is, someone who uses a procedure for detecting certain defects or conditions by listening for normal and abnormal heart, breath, bowel, fetal, and other sounds in the body.

Someone who operates an aircraft.

Refashioned after French aviateur. See aviation for origin of this word.

1. A person exercising absolute authority of any kind or in any sphere; one who authoritatively prescribes a course of action or dictates what is to be done.
2. One who dictates to a writer.

1. Someone who emancipates.
2. Someone who frees others from bondage; for example, "Lincoln is known as the Great Emancipator."

1. A person, usually a professional combatant, a captive, or a slave, trained to entertain the public by engaging in mortal combat with another person, or a wild animal, in the ancient Roman arena; now more like a person engaged in a controversy or debate, especially in public; a disputant.
2. In ancient Rome, a professional fighter who fought another combatant, or a wild animal, in public entertainments which took place in an arena.

Often gladiators were criminals, or slaves, who were equipped with nets, nooses, swords, or other weapons for battle to entertain Romans in the circuses.