hair follicle

A hair follicle is part of the skin that grows hair by packing old cells together. Attached to the follicle is a sebaceous gland, a tiny sebum-producing gland found everywhere except on the palms, lips and soles of the feet. The thicker density of hair, the more sebaceous glands are found. Also attached to the follicle is a tiny bundle of muscle fiber called the arrector pili that is responsible for causing the follicle lissis to become more perpendicular to the surface of the skin, and causing the follicle to protrude slightly above the surrounding skin. This process results in goose bumps (or goose flesh).  Stem cells are located at the junction of the arrector and the follicle, and are principally responsible for the ongoing hair production during a process known as the Anagen stage.
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Hair follicle n. A deep narrow pit that is formed by the tubular invagination of the epidermis and corium and encloses the root of the hair. [more]Hair follicle - Community and Resources

Noun
1. a small tubular cavity containing the root of a hair; small muscles and sebaceous glands are associated with hair follicles
(hypernym) follicle
(part-meronym) sebaceous gland, sebaceous follicle, glandulae sebaceae

A sac from which a hair grows.

[FOL-i-kul]
A shaft or opening on the surface of the skin through which hair grows.