<p><strong>Noun</strong></p><ul><li>any of the numerous fine, usually cylindrical, keratinous filaments growing from the skin of humans and animals; a pilus.</li><li>an aggregate of such filaments, as that covering the human head or forming the coat of most mammals.</li><li>a similar fine, filamentous outgrowth from the body of insects, spiders, etc.</li><li>(Botany) a filamentous outgrowth of the epidermis.</li><li>cloth made of hair from animals, as camel and alpaca.</li><li>a very small amount, degree, measure, magnitude, etc.; a fraction, as of time or space: He lost the race by a hair.</li></ul>