Related Clues:

• Hello or goodbye
• Fifth is one
• Word of welcome
• Street sign abbr.
• Monopoly space: Abbr.
• Letters on letters
• Hadrian's ''Hail!''
• Whittles down
• Park in N.Y.C., e.g.
• Caesar's greeting
• Abbr. on 14-Across
• Hail, classically
• Word of farewell
• Welcome
• Ciao, to Caesar