Star gets ready in the evening (6)
I believe the answer is:
sunset
'the evening' is the definition.
(thesaurus)
'star gets ready' is the wordplay.
'star' becomes 'sun' (Sun is an example).
'gets' says to put letters next to each other.
'ready' becomes 'set' ('set' can be similar in meaning to 'ready').
'sun'+'set'='SUNSET'
'in' is the link.
(Other definitions for sunset that I've seen before include "Describes a declining industry or technology" , "After which day becomes night" , "US nest (anag.)" , "Musical from film about Hollywood" , "Onset of night" .)