A game fish swallows it, look (9)
I believe the answer is:
solitaire
'a game' is the definition.
(I know that solitaire is a type of card game)
'fish swallows it look' is the wordplay.
'fish' becomes 'sole' (sole is a kind of fish).
'swallows' means one lot of letters goes inside another.
'look' becomes 'air' (something might have a certain air or look).
'it'+'air'='itair'
'sole' enclosing 'itair' is 'SOLITAIRE'.
(Other definitions for solitaire that I've seen before include "Bond girl" , "thrush" , "Patience game" , "One-gem ring; one-player game" , "American singer" .)