New puppies possibly born in rubbish receptacle (6,3)
I believe the answer is:
litter bin
'rubbish receptacle' is the definition.
'new puppies possibly born in' is the wordplay.
'new puppies possibly' becomes 'litter'.
'born' becomes 'b'.
'litter'+'b'+'in'='LITTER-BIN'
(Other definitions for litter bin that I've seen before include "refuse to go there" , "trash can" , "waste disposal unit" , "Container for rubbish" , "Waste container" .)