Fund gear - treasury exhausted (5)
I believe the answer is:
kitty
'fund' is the definition.
(I've seen this before)
'gear treasury exhausted' is the wordplay.
'gear' becomes 'kit' (kit is a kind of gear).
'exhausted' says to hollow out the word (remove centre letters) (the word is emptied out or exhausted).
'treasury' with its middle removed is 'ty'.
'kit'+'ty'='KITTY'
(Other definitions for kitty that I've seen before include "Young domestic pet" , "One part of litter queen dropped" , "Cat; fund of money" , "Pool - Katharina?" , "that 6 ac [CAT BURGLAR] steals?" .)