Ran club, possibly in Rutherford (5)
I believe the answer is:
raced
'ran' is the definition.
('race' can be a synonym of 'run')
'club possibly in rutherford' is the wordplay.
'club possibly' becomes 'ace' (the Ace of Clubs).
'in' means one lot of letters goes inside another.
'rutherford' becomes 'rd' (symbol for Rutherford, unit of radioactive decay).
'ace' going inside 'rd' is 'RACED'.
(Other definitions for raced that I've seen before include "Ran fast" , "Cedar (anag)" , "Dashed" , "Went fast" , "Went quickly round" .)