This target includes sun (4)
I believe the answer is:
star
'sun' is the definition.
(thesaurus)
'this target includes' is the wordplay.
'includes' indicates the answer is hidden within the clue.
'STAR' is hidden within 'this target'.
(Other definitions for star that I've seen before include "Brilliant performer?" , "Pointed shape" , "For example, Marilyn Monroe" , "Outstanding person" , "feature in film" .)