Hāir, n.

n. [A-S. hār, O. Fries. hēr, O. H. Ger. & Icel. hār, N. H. Ger. & D. haar, O. D. hāir, Dan. haar, Sw. hār, Goth. as if hēs, allied to Skr. kēśa, and Lat. cæs in cæsaries.]

1Sense 1. The collection or mass of filaments growing from the skin of an animal, and forming an integument or covering for a part of the head or for the whole of the body. In this sense it has no plural.

2Sense 2. One of the above-mentioned filaments, consisting of a long, tubular part, which is free and flexible, and a bulbous root imbedded in the skin. “And draweth new delights with hoary hairs.” Spenser.

3Sense 3. (Bot.) An external prolongation consisting of one or more cells of the vegetable cuticle, of any form, as globular, elongated, or stellated; sometimes containing poison, as in the nettle; sometimes an odorous product (then called glandular hairs), as in the sweetbrier; especially, a long, straight, and distinct filament on the surface of plants. Martyn.

4Sense 4. (Mech.) A spring or other contrivance in a rifle or pistol lock, which, being unlocked by a slight pressure on the trigger, strikes the tumbler-catch, and unlocks the tumbler.

Against the hair, in a rough and disagreeable manner; against the grain. [Obs.]

You go against the hair of your profession. Shak.

— To split hairs, to make distinctions of useless nicety. — Not worth a hair, of no value. — To a hair, with the nicest distinction.