Water cooler?

ICECUBE

Think of what you might drop into a drink to keep it chilled—this one’s a single frozen piece.

The clue "Water cooler?" plays on the idea of something that cools water—literally. Instead of referring to an office water cooler, it hints at what you’d put in water to cool it down: an ice cube. The question mark signals a pun or wordplay, nudging you to think beyond the obvious meaning of "cooler" as a device. It’s a clever twist on a common phrase to lead you to the answer.