Kitty's capsized sailing boat (5)
I believe the answer is:
sloop
'sailing boat' is the definition.
(type of sailing boat)
'kitty's capsized' is the wordplay.
'kitty's' becomes 'pool's' ('pool' can be a synonym of 'kitty').
'capsized' says the letters should be written backwards.
'pools' back-to-front is 'SLOOP'.
(Other definitions for sloop that I've seen before include "Vessel with a single mast" , "one going to sea" , "something that's rigged" , "One-masted sailing boat" , "Single-masted sailing vessel" .)