Old English hær "hair, a hair," from Proto-Germanic *khæran (cf. Old Saxon, Old Norse, Old High German har, Old Frisian her, Dutch and German haar "hair"), perhaps from PIE *ghers- "to stand out, to bristle, rise to a point" (cf. Lithuanian serys "bristle;" see horror).
Spelling influenced by Old Norse har and Old English haire "haircloth," from Old French haire, from Frankish *harja or some other Germanic source (see above). To let one's hair down "become familiar" is first recorded 1850. Phrase hair of the dog that bit you (1540s), homeopathic remedy, is in Pliny.
Any of the cylindrical, keratinized, often pigmented filaments characteristically growing from the epidermis of a mammal.
A growth of such filaments, as that forming the coat of an animal or covering the scalp of a human.
One of the fine hairlike processes of a sensory cell.
To be very open and candid, esp about personal matters: A lot of men that I have been with do not let their hair down/ A small-town beauty shop, where city slickers can really let their hair down
(1.) The Egyptians let the hair of their head and beard grow only when they were in mourning, shaving it off at other times. "So particular were they on this point that to have neglected it was a subject of reproach and ridicule; and whenever they intended to convey the idea of a man of low condition, or a slovenly person, the artists represented him with a beard." Joseph shaved himself before going in to Pharoah (Gen. 41:14). The women of Egypt wore their hair long and plaited. Wigs were worn by priests and laymen to cover the shaven skull, and false beards were common. The great masses of hair seen in the portraits and statues of kings and priests are thus altogether artificial. (2.) A precisely opposite practice, as regards men, prevailed among the Assyrians. In Assyrian sculptures the hair always appears long, and combed closely down upon the head. The beard also was allowed to grow to its full length. (3.) Among the Greeks the custom in this respect varied at different times, as it did also among the Romans. In the time of the apostle, among the Greeks the men wore short hair, while that of the women was long (1 Cor. 11:14, 15). Paul reproves the Corinthians for falling in with a style of manners which so far confounded the distinction of the sexes and was hurtful to good morals. (See, however, 1 Tim. 2:9, and 1 Pet. 3:3, as regards women.) (4.) Among the Hebrews the natural distinction between the sexes was preserved by the women wearing long hair (Luke 7:38; John 11:2; 1 Cor. 11:6), while the men preserved theirs as a rule at a moderate length by frequent clipping. Baldness disqualified any one for the priest's office (Lev. 21). Elijah is called a "hairy man" (2 Kings 1:8) from his flowing locks, or more probably from the shaggy cloak of hair which he wore. His raiment was of camel's hair. Long hair is especially noticed in the description of Absalom's person (2 Sam. 14:26); but the wearing of long hair was unusual, and was only practised as an act of religious observance by Nazarites (Num. 6:5; Judg. 13:5) and others in token of special mercies (Acts 18:18). In times of affliction the hair was cut off (Isa. 3:17, 24; 15:2; 22:12; Jer. 7:29; Amos 8:10). Tearing the hair and letting it go dishevelled were also tokens of grief (Ezra 9:3). "Cutting off the hair" is a figure of the entire destruction of a people (Isa. 7:20). The Hebrews anointed the hair profusely with fragrant ointments (Ruth 3:3; 2 Sam. 14:2; Ps. 23:5; 45:7, etc.), especially in seasons of rejoicing (Matt. 6:17; Luke 7:46).