Awful lout in Bosnia mistakenly gets pardon (10)
I believe the answer is:
absolution
'pardon' is the definition.
(thesaurus)
'awful lout in bosnia mistakenly' is the wordplay.
'awful' indicates anagramming the letters.
'in' indicates putting letters inside.
'mistakenly' indicates anagramming the letters.
'lout' with letters rearranged gives 'olut'.
'bosnia' with letters rearranged gives 'absion'.
'olut' going within 'absion' is 'ABSOLUTION'.
'gets' acts as a link.
(Other definitions for absolution that I've seen before include "Forgiveness" , "pardon" , "acquittal" , "discharge" , "Release from guilt" .)