Dic: water cooler, water-cooler

• Three out of four Americans watched Roots, and then the next day could talk about race relations at the water cooler.

1. N-SING | Water cooler is used in expressions that refer to the informal conversations that people have in their office or workplace.
2. [US informal] indicating the kind of informal conversation among office staff that takes place at such a dispenser: water-cooler conversations

.... Cobuild, Collins English