Pile of lumpy remains (4)
I believe the answer is:
pyre
'pile' is the definition.
(pyre is a kind of pile)
'of lumpy remains' is the wordplay.
'of' indicates a hidden word.
'PYRE' is hidden in the letters of 'lumpy remains'.
(Other definitions for pyre that I've seen before include "On which a body is burned" , "Funeral mound" , "Wood pile for a funeral rite" , "Funeral conflagration" , "A funeral fire for 27 Down" .)