Kitty in new top (3)
I believe the answer is:
pot
'kitty' is the definition.
(both can mean a shared fund)
'new top' is the wordplay.
'new' is an anagram indicator.
'top' with letters rearranged gives 'POT'.
'in' acts as a link.
(Other definitions for pot that I've seen before include "Substance from the sap of trees" , "Cylindrical container" , "prize" , "Ceramic vessel" , "Container for 23" .)