Fool exposed Italians in front of two Americans (9)
I believe the answer is:
ignoramus
'fool' is the definition.
(I've seen this before)
'exposed italians in front of two americans' is the wordplay.
'exposed' indicates the central letters (the inside of the word is exposed).
'italians' becomes 'signori' (I've seen this before).
'in front of two' becomes 'am' (I can't explain this - if you can you should give a lot more credence to this answer).
'americans' becomes 'US' (United States).
The centre of 'signori' is 'ignor'.
'ignor'+'am'+'us'='IGNORAMUS'
Can you help me to learn more?
(Other definitions for ignoramus that I've seen before include "Fool" , "I wouldn't know" , "unwitting person" , "One is not intelligent" , "Stupid person" .)