Mortification due to article impounded by coppers? (7)
I believe the answer is:
penance
'mortification' is the definition.
(thesaurus)
'article impounded by coppers?' is the wordplay.
'article' becomes 'an' (indefinite article).
'impounded by' means one lot of letters goes inside another.
'coppers?' becomes 'pence' (copper is a kind of penny).
'an' put inside 'pence' is 'PENANCE'.
'due to' acts as a link.
(Other definitions for penance that I've seen before include "Remorse" , "Reparation" , "Punishment inflicted on oneself" , "Hardship" , "Act of penitence" .)