Arrest of Briton abroad (3)
I believe the answer is:
nab
'arrest' is the definition.
(synonyms)
'of briton abroad' is the wordplay.
'of' says the answer is hidden in the clue.
'NAB' is hidden within 'briton abroad'.
(Other definitions for nab that I've seen before include "Run in" , "nail" , "Pinch" , "Apprehend" , "Capture (slang)" .)