Cobblers can make a lot of money covering pair of feet (6)
I believe the answer is:
piffle
'cobblers' is the definition.
(both can mean nonsense)
'a lot of money covering pair of feet' is the wordplay.
'a lot of money' becomes 'pile' (I've seen this in another clue).
'covering' means one lot of letters goes inside another.
'pair' says to double the letters.
'feet' says to take the final letters (I've seen 'foot' mean this (in a down clue, the bottom letter)).
The last letter of 'of' is 'f'.
'f' doubled is 'ff'.
'pile' going around 'ff' is 'PIFFLE'.
'can make' acts as a link.
(Other definitions for piffle that I've seen before include "Hogwash" , "Trivial nonsense" , "Twaddle" , "Rubbish, nonsense" , "Balderdash" .)