Race segment (3)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
'race segment' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for leg that I've seen before include "Section of journey; limb" , "Stage (of race)" , "Poultry portion" , "Gigot" , "Lower limb" .)