Billiard ball that’s not spotted? (5)
I believe the answer is:
white
'billiard ball' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Maybe there's an association between them I don't understand?
I don't understand the remainder of the clue.
(Other definitions for white that I've seen before include "Neutral colour" , "See 9" , "Reflecting virtually all light" , "Wit, he? (anag.)" , "Opponent of six dn (chess)" .)