Stellar, like short refrain (6)
I believe the answer is:
astral
'stellar' is the definition.
(synonyms)
'like short refrain' is the wordplay.
'like' becomes 'as'.
'short' means to remove the last letter.
'refrain' becomes 'tra-la' (tra-la is a kind of refrain).
'trala' with its final letter taken away is 'tral'.
'as'+'tral'='ASTRAL'
(Other definitions for astral that I've seen before include "Characteristic of stars" , "Universal" , "Pertaining to the stars" , "like a star" , "19 [STELLAR]" .)