Lore rubbished in part (4)
I believe the answer is:
role
'part' is the definition.
(eg a theatrical role)
'lore rubbished' is the wordplay.
'rubbished' indicates anagramming the letters.
'lore' with letters rearranged gives 'ROLE'.
'in' is the link.
(Other definitions for role that I've seen before include "Part (in drama)" , "Stage part" , "Acting part" , "Part played (in life?)" , "Impersonation" .)