Father uplifted after he makes a pile (4)
I believe the answer is:
heap
'a pile' is the definition.
(I know that slag heap can be written as heap)
'father uplifted after he' is the wordplay.
'father' becomes 'pa' (pa can mean dad or father).
'uplifted' is a reversal indicator.
'after' says to put letters next to each other.
'pa' backwards is 'ap'.
'ap' put after 'he' is 'HEAP'.
'makes' is the link.
(Other definitions for heap that I've seen before include "Loose pile" , "Pile (of scrap?)" , "Rough pile" , "car on its last legs" , "Pile, stack" .)