Initially such indolence brought about European corruption (10)
I believe the answer is:
sleaziness
'corruption' is the definition.
(I've seen this before)
'initially such indolence brought about european' is the wordplay.
'initially' suggests taking the first letters.
'indolence' becomes 'laziness' (synonyms).
'brought about' indicates putting letters inside.
'european' becomes 'e' (abbreviation e.g. EU).
The initial letter of 'such' is 's'.
'laziness' enclosing 'e' is 'leaziness'.
's'+'leaziness'='SLEAZINESS'
(Other definitions for sleaziness that I've seen before include "squalor" , "corruption" .)