Definition of "Hair" :

noun: a filamentous projection or process on an organism

noun: cloth woven from horsehair or camelhair; used for upholstery or stiffening in garments

noun: any of the cylindrical filaments characteristically growing from the epidermis of a mammal

"There is a hair in my soup."

noun: a covering for the body (or parts of it) consisting of a dense growth of threadlike structures (as on the human head); helps to prevent heat loss

"He combed his hair."

noun: filamentous hairlike growth on a plant

noun: a very small distance or space

"They escaped by a hair's-breadth."