Related Clues:

• Omicrons' predecessors
• Frat letters
• Particle displacement symbols, in physics
• Long E's, in Greek
• Jumbles
• Letters from Greece
• Letters from overseas
• Hellenic letters
• H H H
• Circle ratios
• Some sorority women
• Xis' predecessors
• Airport info, for short
• Cockpit guesses, for short
• Magnum and others: Abbr.