Hair

1. Any of the cylindrical, keratinized, often pigmented filaments characteristically growing from the epidermis of a mammal. Bears have heavy long hair to protect them from the cold.
2. A growth of such filaments, as that forming the coat of an animal or covering the scalp of a human being. Many ladies wash their hair frequently.
3. A minute distance or narrow margin. He won the race by just a hair.