Star ready for the evening (6)
I believe the answer is:
sunset
'the evening' is the definition.
(thesaurus)
'star ready' is the wordplay.
'star' becomes 'sun' (the Sun is a star).
'ready' becomes 'set' (set can mean ready or prepared).
'sun'+'set'='SUNSET'
'for' acts as a link.
(Other definitions for sunset that I've seen before include "This in west" , "Twilight time" , "Evening glow" , "Musical from film about Hollywood" , "star not in the ascendant at this time" .)