Keep value for city (4,5)
I believe the answer is:
fort worth
'city' is the definition.
(Fort Worth is an example)
'keep value' is the wordplay.
'keep' becomes 'fort' (I've seen this in other clues).
'value' becomes 'worth' (I've seen this before).
'fort'+'worth'='FORT WORTH'
'for' acts as a link.
(Other definitions for fort worth that I've seen before include "Texas city" , "US city" .)