Attract topless lady, ultimately vain (5)
I believe the answer is:
empty
'vain' is the definition.
(I've seen this before)
'attract topless lady ultimately' is the wordplay.
'attract' becomes 'tempt' (I've seen this in other clues).
'topless' means to remove the first letter.
'ultimately' indicates one should take the final letters.
The last letter of 'lady' is 'y'.
'tempt' with its initial letter taken away is 'empt'.
'empt'+'y'='EMPTY'
(Other definitions for empty that I've seen before include "(Of words) lacking sincerity" , "Cleared out" , "Arabic quarter" , "Void; vacant" , "Dead man" .)