Accustomed to American education (4)
I believe the answer is:
used
'accustomed' is the definition.
(thesaurus)
'american education' is the wordplay.
'american' becomes 'us'.
'education' becomes 'ed' (abbreviation - e.g. sex ed).
'us'+'ed'='USED'
'to' acts as a link.
(Other definitions for used that I've seen before include "Enjoyed" , "Accustomed - exploited" , "Subject to exploitation" , "not got directly" , "Dues (anag.)" .)