The phrase "putting cork in" means to stop or seal something. The opposite of this would be to open or release something. Antonyms for putting cork in could include phrases such as 'unplugged,' 'let loose,' 'unleashed,' 'unlocked,' 'freed,' or 'unsealed.' For example, instead of putting cork in a bottle, one might say they released the contents or uncorked the bottle. Similarly, instead of putting cork in a hole, one might say they unplugged the opening or unsealed the entrance. Antonyms for putting cork in represent the opposite action to closing or stopping something, indicating an opening or release of energy, pressure or substances.