Spinner spinning nine out to restrict runs (8)
I believe the answer is:
neutrino
'spinner' is the definition.
(I've seen this before)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for neutrino that I've seen before include "Spinner" , "Uncharged elementary particle" , "Small piece of matter" , "There's almost nothing to it!" , "This barely affects anything" .)