Literal Translation
To play/count for butter
Actual Meaning
To play/count for nothing
Etymology
To be ‘of butter’ (du beurre) meant to be worthless in the 19th century. Indeed, ‘vendre du beurre’ meant to be an outcast. Nowadays, the expression is mostly used in games, ‘un tour pour du beurre’ means to play a round for nothing before the real game begins.