Formal:
* Ice water: This is the most common and straightforward option.
* Freezing water: Emphasizes the extremely cold temperature.
Descriptive:
* Chilled water: This suggests a refreshing coolness, perhaps from a refrigerator.
* Glacial water: This implies a water source from a glacier, emphasizing its purity and coldness.
* Iced water: This is similar to "ice water" but emphasizes the presence of ice cubes.
Figurative:
* Arctic water: This is a metaphorical term suggesting extreme coldness.
The best option depends on the specific meaning you want to convey.