The speed of the runner-up? (6-4)
I believe the answer is:
second-rate
'the' is the definition.
I can't tell whether this definition defines the answer.
'speed of the runner-up?' is the wordplay.
I cannot quite understand how this works, but
'speed' could be 'rate' (both can mean pace) and 'rate' is found in the answer.
'of' could be 'o' and 'o' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for second-rate that I've seen before include "Substandard" , "Poor" , "Inferior" , "Shoddy" , "Of mediocre quality" .)