Dissatisfied fellow delivered a lecture on corruption (10)
I believe the answer is:
frustrated
'dissatisfied' is the definition.
(thesaurus)
'fellow delivered a lecture on corruption' is the wordplay.
'fellow' becomes 'F' (abbreviation - of a society etc.).
'delivered a lecture' becomes 'rated' (rate can mean to lecture or rebuke).
'on' means one lot of letters go next to another.
'corruption' becomes 'rust' (rust is a kind of decay or corruption).
'rated' after 'rust' is 'rustrated'.
'f'+'rustrated'='FRUSTRATED'
(Other definitions for frustrated that I've seen before include "Foiled" , "Disappointingly unsuccessful" , "Prevented from progressing" , "Having a sense of discouragement and dissatisfaction" , "Disheartened" .)