A card game, say (4)
I believe the answer is:
snap
This clue might be a double definition.
'a card game' is the first definition.
(simple card game)
'say' is the second definition.
The definition and answer can be both to do with communicating as well as being verbs in their base form.
Perhaps they are linked in a way I don't understand?
Can you help me to learn more?
(Other definitions for snap that I've seen before include "Snarl at - photograph" , "Pans out in simple card game" , "Break - children's card game" , "Break suddenly and abruptly" , "that's a copy!" .)