All actors in show alternatively star (6)
I believe the answer is:
castor
'star' is the definition.
(Castor is an example)
'all actors in show alternatively' is the wordplay.
'actors' anagrams to 'CASTOR'.
However, I am unsure how this is indicated.
Can you help me to learn more?
(Other definitions for castor that I've seen before include "Furniture wheel; sort of oil" , "Powdered sugar" , "Pollux's twin" , "excellent once at the Gabba" , "Trolley wheel" .)