hair

Etymology

From Middle English her, heer, hær, from Old English hǣr, from Proto-West Germanic *hār, from Proto-Germanic *hērą (“hair”). Cognate with Saterland Frisian Hier (“hair”), West Frisian hier (“hair”), Dutch haar (“hair”), German Low German Haar (“hair”), German Haar (“hair”), Swedish, Danish and Norwegian hår (“hair”), Icelandic hár (“hair”), Finnish hius (“hair”). Eclipsed non-native Middle English cheveler, chevelere (“hair”), borrowed from Old French chevelëure (“hair, head-hair, coiffure, wig”). The modern spelling with ai is not a regular representation of the vowel developed from Middle English. Rather, it is from Middle English here (haircloth) influenced by Old French haire.

noun

1. (countable) A pigmented filament of keratin which grows from a follicle on the skin of humans and other mammals.
2. (uncountable) 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.
   In the western world, women usually have long hair while men usually have short hair.
3. (zoology, countable) 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.
4. (botany, countable) A cellular outgrowth of the epidermis, consisting of one or of several cells, whether pointed, hooked, knobbed, or stellated.
   Internal hairs occur in the flower stalk of the yellow frog lily (Nuphar).
5. (countable) Any slender, flexible outgrowth, filament, or fiber growing or projecting from the surface of an object or organism.
   (uncountable, by extension) The collection or mass of such outgrowths, filaments, or fibers growing or projecting from the surface of an object or organism.
6. (countable, engineering, firearms) 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.
7. (obsolete) Haircloth; a hair shirt.
   She, ful devout and humble in hir corage, / Under hir robe of gold, that sat ful faire, / Hadde next hir flessh yclad hir in an haire. c. 1390, Geoffrey Chaucer, “The Second Nun's Tale”, in The Canterbury Tales
8. (countable) Any very small distance, or degree; a hairbreadth.
   Just a little louder please—turn that knob a hair to the right.
9. (slang, uncountable) Complexity; difficulty; the quality of being hairy.
   January 2014, Barack Obama, quoted in "Going the Distance" by David Remnick, in The New Yorker Having said all that, those who argue that legalizing marijuana is a panacea and it solves all these social problems I think are probably overstating the case. There is a lot of hair on that policy.

verb

1. (transitive) To remove the hair from.
   Now know ye, that in compliance with the said proviso, we the said John Cant and John Millar do hereby declare that our said invention of a new method of tanning leather is described in the manner following : that our method of preparing hides and skins by liming, hairing, fleshing, and baiting, is the same as that in use by the most experienced tanners; that is to say: All leather that is to be dressed or curried, we use the operation of what tanners call baiting, for this reason; that the leather when curried should carry a sufficient quantity of oil, and dry a good colour. 1808, The Repertory of Patent Inventions, page 90
   By his method raw hides, after hairing and baiting, are converted into leather in less than thirty hours. 1825, American Mechanics' Magazine - Volume 2, page 71
   I took 25 hides out of the Lime with Stephens help I haired them and fleshed them 1971, Reuben King, Virginia S. Wood, Ralph V. Wood, The Reuben King Journal, 1800-1806, page 49
2. (intransitive) To grow hair (where there was a bald spot).
   He has haired up and healed over. 1863, Yankee-notions - Volume 12, page 312
   It has haired over nicely. There are no bad results from it in any way whatever that I can detect. 1887, National Stockman and Farmer - Volume 11, page 7
   The bald patch on his hip was hairing over and he no longer limped. 1992, Hugh Ruppersburg, Georgia Voices: Fiction, page 492
3. (transitive) To cause to have or bear hair; to provide with hair
   THE following classes of fiber are employed for hairing dolls : human hair, mohair, cross-bred wool, horsehair, hog-bristle, unspun cotton. Human hair is only used for hairing dolls of an extremely expensive class. 1937, Dyestuffs - Volume 35, Issue 1, page 1
   So they did three different sculptures and then ran the masks and painted them, haired them, and sent them out to us. 2014, Lee Karr, Greg Nicotero, The Making of George A. Romero's Day of the Dead
   The winter had haired them like llamas, the sleet had worked no hardship, as a horse paws to the grass, and any concern for the outside saddle stock was needless. 2017, Andy Adams, Wells Brothers: The Young Cattle Kings
4. To string the bow for a violin.
   The bow is now haired, and all that remains to make it ready for use is to rosin it. 1896, Henry Saint-George, The Bow, Its History, Manufacture & Use, page 96
   The tools used for hairing a bow by various reparimen can be unlimited in their selection. A bowmaker has a different attitude toward hairing than a repairman and this I believe reflects the type of the finished job that is done. 1969, John Alfred Bolander, Violin bow making, page 105
   To hair a bow, a hank of horse hair (A) is selected and combed so that all hairs are parallel to each other. 2015, Michael J. Pagliaro, The String Instrument Owner's Handbook, page 108