Spots Bill, one without the ball (4)
I believe the answer is:
acne
'spots' is the definition.
(I've seen this before)
'bill one without the ball' is the wordplay.
'bill' becomes 'ac'.
'without' indicates named letters should be taken away.
'the ball' becomes 'o'.
'one' with 'o' taken out is 'ne'.
'ac'+'ne'='ACNE'
(Other definitions for acne that I've seen before include "Face problems" , "Skin condition associated with pimples" , "Problem to face in" , "Teenage skin blemish" , "Teenage spots" .)