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

- he combed his hair

- each hair consists of layers of dead keratinized cells

Definition categories: body

2. a very small distance or space

- they escaped by a hair's-breadth

Similar word(s): hairsbreadth, whisker

Definition categories: quantity

3. filamentous hairlike growth on a plant

Similar word(s): fuzz, tomentum

Definition categories: plant, enation

4. any of the cylindrical filaments characteristically growing from the epidermis of a mammal

- there is a hair in my soup

Similar word(s): pilus

Definition categories: body, filament, filum

5. cloth woven from horsehair or camelhair; used for upholstery or stiffening in garments

Similar word(s): haircloth

Definition categories: man–made, cloth, fabric, material, textile

6. a filamentous projection or process on an organism

Definition categories: animal, appendage, outgrowth, process

Sentences with hair as a noun:

- In the western world, women usually have long hair while men usually have short hair.

- Internal hairs occur in the flower stalk of the yellow frog lily (Nuphar).

- Just a little louder please—turn that knob a hair to the right.