Repair shoe's lump underfoot? (6)
I believe the answer is:
cobble
I believe this clue is a double definition.
'repair shoe's' is the first definition.
'lump underfoot?' is the second definition.
(as in a cobbled road)
(Other definitions for cobble that I've seen before include "Mend shoes with a paving stone?" , "Stone used in road surfaces" , "Work on last" , "Road-surfacing stone" , "Rounded stone once commonly used for paving" .)