Glug?
Water Bottle: Vessel to carry clean water in.
Water Bottle: As a "raw water" bottle, it is a vessel to carry untreated water in. This can serve as a reservoir of water to treat later, when making a dry camp, or can be used as-is for bathing.
Water Bottle: Either of the above, but you'd better keep track of which is which.
Originally, a water bottle was an appurtenance of the effete, but later became accepted as mandatory equipment, replacing metal canteens, mason jars, and lapping directly from streams at the time when hikers came to think of "bottle" and "Nalgene container" as synonyms, and began to fear untreated water.
Currently most backpackers will not recognize anything as a water bottle unless it weighs at least four ounces, costs at least $8, and comes in designer colors.
Soft drink bottles are equivalent, except that soft drink bottles weigh only about an ounce, cost a dollar or two, and come with free sugary, fizzy drinks inside.
Those who don't want to pay anything at all can scrounge soft drink bottles from friends or trash bins (and give them a good wash before first use).