Poor firm pockets a pile (6)
I believe the answer is:
cheapo
'poor' is the definition.
(cheapo can mean of poor quality)
'firm pockets a pile' is the wordplay.
'firm' becomes 'co' (a firm is a company).
'pockets' indicates putting letters inside.
'a pile' becomes 'heap' (synonyms).
'co' placed around 'heap' is 'CHEAPO'.
(Other definitions for cheapo that I've seen before include "of little value" , "Inferior product" , "not expensive" , "Mickey Mouse" , "Shoddy" .)