Joint English and Yankee game (6)
I believe the answer is:
hockey
'game' is the definition.
(I know that hockey is a type of athletic game)
'joint english and yankee' is the wordplay.
'joint' becomes 'hock' (joint of meat).
'english' becomes 'E' (abbreviation as in OED).
'and' says to put letters next to each other.
'yankee' becomes 'Y' (phonetic alphabet: alpha, bravo, charlie etc.).
'hock'+'e'+'y'='HOCKEY'
(Other definitions for hockey that I've seen before include "Field game played with curved sticks like hurleys" , "Eleven-a-side field game" , "Stick and ball game" , "Game started by a bully!" , "Game using stick with curved end" .)