Quiet American', uncle recalled inwardly, is a triumph (5)
I believe the answer is:
smash
'a triumph' is the definition.
(thesaurus)
'quiet american' uncle recalled inwardly' is the wordplay.
'quiet american'' becomes 'sh' (I can't justify this - if you can you should give a lot more credence to this answer).
'uncle' becomes 'sam' (Uncle Sam is an example).
'recalled' says the letters should be written backwards (to recall can mean to bring something back).
'inwardly' is an insertion indicator.
'sam' reversed gives 'mas'.
'sh' enclosing 'mas' is 'SMASH'.
'is' acts as a link.
Can you help me to learn more?
(Other definitions for smash that I've seen before include "Overarm volley" , "Shatter violently" , "Break suddenly into little pieces" , "Break like a glass or cup" , "Shatter, break up" .)