Catches up in The West End (4)
I believe the answer is:
nets
'catches' is the definition.
(netting is a kind of catching)
'up in the west end' is the wordplay.
'up' says the letters should be written in reverse (in down clue: letters go upwards).
'in' indicates a hidden word.
'sten' is hidden within 'west end'.
'sten' reversed gives 'NETS'.
(Other definitions for nets that I've seen before include "Traps, to catch fish say" , "Practice pitches (cricket)" , "Cricket practice venue" , "(Period for) cricket practice" , "'Traps for 29 dn, say (4)'" .)