Possesses topless dresses (4)
I believe the answer is:
owns
'possesses' is the definition.
('own' can be a synonym of 'possess')
'topless dresses' is the wordplay.
'topless' means to remove the first letter.
'dresses' becomes 'gowns' (gown is a kind of dress).
'gowns' with its initial letter taken off is 'OWNS'.
(Other definitions for owns that I've seen before include "uses" , "Admits possession" , "Has possession of by right" , "Possesses" , "Confesses" .)