Game — variety of grouse? Lovely (8)
I believe the answer is:
gorgeous
'lovely' is the definition.
(I've seen this before)
'game variety of grouse?' is the wordplay.
'game' becomes 'go game' (go is a board game).
'variety of' indicates anagramming the letters.
'grouse' with letters rearranged gives 'rgeous'.
'go'+'rgeous'='GORGEOUS'
(Other definitions for gorgeous that I've seen before include "delightful?" , "Lovely" , "Stunning" , "Sumptuously beautiful" , "Showy" .)