A pigmented filament of keratin which grows from a follicle on the skin of humans and other mammals.
The collection or mass of such growths growing from the skin of humans and animals, and forming a covering for a part of the head or for any part or the whole body.
A slender outgrowth from the chitinous cuticle of insects, spiders, crustaceans, and other invertebrates. Such hairs are totally unlike those of vertebrates in structure, composition, and mode of growth.
A cellular outgrowth of the epidermis, consisting of one or of several cells, whether pointed, hooked, knobbed, or stellated.
Any slender, flexible outgrowth, filament, or fiber growing or projecting from the surface of an object or organism.
A locking spring or other safety device in the lock of a rifle, etc., capable of being released by a slight pressure on a hair-trigger.
Any very small distance, or degree; a hairbreadth.
(slang) Complexity; difficulty; the quality of being hairy.