Inventor moved onside (6)
I believe the answer is:
edison
'inventor' is the definition.
(Edison is an example)
'moved onside' is the wordplay.
'moved' is an anagram indicator.
'onside' with letters rearranged gives 'EDISON'.
(Other definitions for edison that I've seen before include "US inventor of phonograph, electric light etc." , "Incandescent light inventor" , "Thomas --, US?inventor" , "Inventor with over 1,000 US patents to his name, d. 1931" , "Thomas Alva -, US inventor" .)