hair definition

1. 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
• examples: he combed his hair
• examples: each hair consists of layers of dead keratinized cells
2. a very small distance or space
• examples: they escaped by a hair's-breadth
• examples: they lost the election by a whisker
3. filamentous hairlike growth on a plant
• examples: peach fuzz
4. any of the cylindrical filaments characteristically growing from the epidermis of a mammal
• examples: there is a hair in my soup
5. cloth woven from horsehair or camelhair; used for upholstery or stiffening in garments
6. a filamentous projection or process on an organism