Related Clues:

• That bird is forever in the beer
• It's often repeated in a calorie, on the inverse unit
• Never varying
• Going on and on outside without 'The Times'?
• Not bound by 20-Across
• Neverending
• Unfading
• Tireless
• Always faithful?
• Regular talk of thieves, perhaps, hiding on road
• Faithful, but getting new man into bed
• Log base with bird on a line is constant
• 10 with real potential never finishing
• Enter failure against article by student out of time
• The beginning of Lowry's Under the 17 down, without hesitation, is timeless