OK splits for each card game (5)
I believe the answer is:
poker
'card game' is the definition.
(poker is a kind of card game)
'ok splits for each' is the wordplay.
'splits' is an insertion indicator.
'for each' becomes 'per' (I've seen this before).
'ok' placed within 'per' is 'POKER'.
(Other definitions for poker that I've seen before include "Ashes stirred by this" , "Rod; betting game" , "Fire prod; game" , "A game for the fireplace implement" , "Fire iron and card game" .)