A vacant senseless fool (3)

I believe the answer is:

ass

'fool' is the definition.
(ass is a kind of fool)

'a vacant senseless' is the wordplay.
'vacant' means to remove the middle letters.
'senseless' with its centre removed is 'ss'.
'a'+'ss'='ASS'

(Other definitions for ass that I've seen before include "Dolt" , "Silly fool or beast of burden" , "Animal; fool" , "Charlie" , "Bottom, temporarily" .)

I've seen this clue in The Times.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.