Well someone can made something out of 100% water that can then be eaten. But seriously, if water can be considered nutrient, then yeah it is a food.
In anabolic metabolism that involve water, then yes water is food. In such case then water has potential calories just like any molecules with hydrogen bonds.
Yes and anabolic steroids can cause ROAD RAGE. Ordinary clear clean water has 0 fats 0 calorific value.