Confused American girl with more garbled nonsense (9)
I believe the answer is:
rigmarole
'garbled nonsense' is the definition.
(I've seen this before)
'confused american girl with more' is the wordplay.
'confused' is an anagram indicator.
'american' becomes 'a' (common abbreviation - e.g. in organisation names).
'with' is a charade indicator (letters next to each other).
'a'+'girl'='agirl'
'agirl' after 'more' is 'moreagirl'.
'moreagirl' is an anagram of 'RIGMAROLE'.
(Other definitions for rigmarole that I've seen before include "boring series" , "Long, rambling story" , "Long, rambling statement or complicated procedure" , "Lengthy and complicated procedure" , "Nonsensical procedure" .)