Article concealed by players before a game (7)
I believe the answer is:
canasta
'game' is the definition.
(canasta is a kind of game)
'article concealed by players before a' is the wordplay.
'article' becomes 'an' (indefinite article).
'concealed by' means one lot of letters goes inside another.
'players' becomes 'cast' (group of actors).
'before' says to put letters next to each other.
'an' going within 'cast' is 'canast'.
'canast'+'a'='CANASTA'
(Other definitions for canasta that I've seen before include "Card game -- as an act (anag)" , "Card game at a scan" , "Card game like rummy" , "Rummy-like card-game" , "Card game of the rummy family" .)