Related Clues:

• There's nothing in the idol to recommend it
• Tip of the S?
• Just the tip of the L - not the l - by the sound of it
• Just the tip or SSSE, perhaps
• The tip that London gets, by the sound of it
• Not mean to give this S, perhaps
• Just the tip of the capital S, by the sound of it
• Together with 23 down, that could be a pretty thorough search
• This for nothing is worthless with nothing in 21 across
• The right sort of start for 36 across
• The wood for the race is OK
• Take a tip from this that it's L, not 1
• The tip of L not 1, by the sound of it
• Go and do it up - OK?
• The tip of S, rather than s, by the sound of it