Apprehend in Downton Abbey (3)
I believe the answer is:
nab
'apprehend' is the definition.
(synonyms)
'in downton abbey' is the wordplay.
'in' indicates the answer is hidden within the clue.
'NAB' can be found hidden inside 'downton abbey'.
(Other definitions for nab that I've seen before include "Take" , "nail" , "Catch (a felon)" , "Catch; grab suddenly" , "Seize quickly" .)