Ringing can fool American (8)
I believe the answer is:
tinnitus
'ringing' is the definition.
(thesaurus)
'can fool american' is the wordplay.
'can' becomes 'tin' ('tin' can be a synonym of 'can').
'fool' becomes 'nit' (I've seen this before).
'american' becomes 'us'.
'tin'+'nit'+'us'='TINNITUS'
(Other definitions for tinnitus that I've seen before include "Condition in which there is constant ringing in the ears" , "problem for audience" , "Hearing ailment" , "annoyance to the ear" , "Unpleasant noise" .)