American detained by courts in European country (7)
I believe the answer is:
austria
'european country' is the definition.
(Austria is an example)
'american detained by courts' is the wordplay.
'american' becomes 'us'.
'detained by' indicates putting letters inside (I've seen this in other clues).
'courts' becomes 'atria' (atrium is a kind of court).
'us' placed within 'atria' is 'AUSTRIA'.
'in' acts as a link.
(Other definitions for austria that I've seen before include "Central European republic" , "European nation" , "Us tiara found in a European state" , "USA art I send to European state" , "Its ruling house was the Hapsburgs" .)