Outstanding giveaway in Hong Kong, perhaps (7)
I believe the answer is:
stellar
'outstanding' is the definition.
(thesaurus)
'giveaway in hong kong perhaps' is the wordplay.
'giveaway' becomes 'tell' (an unconscious signal which gives away information).
'in' indicates putting letters inside.
'hong kong perhaps' becomes 'sar' (special administrative region).
'tell' going inside 'sar' is 'STELLAR'.
(Other definitions for stellar that I've seen before include "Wonderful" , "Excellent - shining bright?" , "Starry" , "High-class" , "of celebrities" .)