City walls in Split survive (4)
I believe the answer is:
last
'survive' is the definition.
(I know that survive can be written as last)
'city walls in split' is the wordplay.
'city' becomes 'LA' (Los Angeles).
'walls in' says to hollow out the word (remove centre letters).
'split' with its centre removed is 'st'.
'la'+'st'='LAST'
(Other definitions for last that I've seen before include "Piece of cobbler's equipment" , "Most unlikely" , "part of Oxford's restoration with this?" , "The cobbler's equipment will endure" , "stay at the back" .)