Mainly describes the quality of water, often referring to its safety for human consumption. I always check if the tap water is potable when I travel to a new country.
Pro Tip 2/3
Not Just Clear
Clear water isn't always potable. Potable means it's been tested and confirmed to be safe. Despite the stream's clarity, the hikers questioned if it was potable.
Pro Tip 3/3
Not Flavor
Potable doesn't refer to taste. Water can taste bad but still be potable. The sulfur-rich water was potable, albeit with an unpleasant taste.