1. Rolex Cosmograph Daytona: This is the most common meaning. It refers to a specific model of Rolex wristwatch known as the Cosmograph Daytona. This chronograph is a highly sought-after timepiece, known for its precision, durability, and association with motorsport and racing.

2. A general term for a device that maps the cosmos: In a more general sense, "cosmograph" could theoretically refer to any device that allows for mapping or charting the universe. This term is less common and less specific than the Rolex model.

So, when someone says "Cosmograph," they are most likely referring to the Rolex Cosmograph Daytona.

If you want to be sure, you can ask for clarification: "Do you mean the Rolex Cosmograph Daytona or something else?"