Possible Clues:

• Description of ring road — part that's spoken about
• Of course it sounds an alternative piece of a half century
• Having spoken about segment of round-the-world trip
• Like a ring road
• Some Labrador bit a lout going round the city
• Road brother's taken round country is endless
• Circuitous
• In a circular path
• What an electron occupies in an atom
• M25, maybe -- what's said about small section?