Places he leaves hats? (9)
I believe the answer is:
addresses
'places' is the definition.
(addressing is a kind of placing)
'he leaves hats?' is the wordplay.
'he' becomes 'Ad'.
'leaves hats?' becomes 'dresses' (I can't justify this - if you can you should give a lot more credence to this answer).
'ad'+'dresses'='ADDRESSES'
Can you help me to learn more?
(Other definitions for addresses that I've seen before include "Places where people can be found" , "Makes a speech to" , "Gives a speech to" , "Speaks to, a crowd perhaps" , "Places to live" .)