Aristotle Onassis was a Greek shipping magnate and billionaire who was born in 1906. He is best known for his marriage to Jacqueline Kennedy, the widow of President John F. Kennedy. The crossword solution for Aristotle Onassis is SOCRATES, an ancient Greek philosopher who was one of the most influential figures in Western philosophy. Socrates is credited with laying the foundations of modern Western philosophy and is widely considered to be one of the greatest thinkers of all time.