Essential nutrients refers to classes of nutrients found in food. Essential nutrients are simply those that are vital for the normal growth, maintenance and development of the body. There might be a slight confusion about essential nutrients that must be addressed.
Definition of waterproof for English Language Learners. : 1  designed to prevent water from entering or passing through. : 2  designed so that water alone will not remove it.
Of course, as with any material that is water proof, to maintain waterproof integrity, the material must be handled and sewn in a way to preserve it's waterproof qualities, like glueing instead of sewing, or using a silicon cualking over stitching points to fill the holes made by the sewing needle.