The Jewish men, except Nazarites, Numbers 6:5,9, and cases like that of Absalom, 2 Samuel 14:26, cut their hair moderately short, 1 Corinthians 11:14, and applied fragrant ointments to it, Exodus 30:30-33 Psalms 23:5 Ecclesiastes 9:8. In mourning they wholly neglected it, or shaved it close, or plucked it out by handfuls, Jeremiah 7:29. Women prized a fine head of hair, and plaited, perfumed, and decked it in many ways, Isaiah 3:18,24 1 Corinthians 11:15, so much as to call for apostolic interdictions, 1 Timothy 2:9 1 Peter 3:9. "Hair like women’s" characterized the locusts of antichrist, Revelation 9:8. Lepers when cleansed, and Levites, on their consecration, shaved the whole body, Leviticus 13:1-59 14:8,9.
Source: ATS Bible Dictionary
Hair
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 (Genesis 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.
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.
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 Corinthians 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 Timothy 2:9, and 1 Peter 3:3, as regards women.)
Among the Hebrews the natural distinction between the sexes was preserved by the women wearing long hair (Luke 7:38; John 11:2; 1 Corinthians 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 (Leviticus 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 Samuel 14:26); but the wearing of long hair was unusual, and was only practised as an act of religious observance by Nazarites (Numbers 6:5; Judges 13:5) and others in token of special mercies (Acts 18:18).
In times of affliction the hair was cut off (Isaiah 3:17,24; 15:2; 22:12; Jeremiah 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 (Isaiah 7:20). The Hebrews anointed the hair profusely with fragrant ointments (Ruth 3:3; 2Sam 14:2; Psalms 23:5; 45:7, etc.), especially in seasons of rejoicing (Matthew 6:17; Luke 7:46).
Source: Easton's Bible Dictionary
Hair
HAIR, n.
1. A small filament issuing from the skin of an animal, and from a bulbous root. Each filament contains a tube or hollow within, occupied by a pulp or pith, which is intended for its nutrition,and extends only to that part which is in a state of growth.
When hair means a single filament,it has a plural,hairs.
2. The collection or mass of filaments growing from the skin of an animal, and forming an integument or covering; as the hair of the head. Hair is the common covering of many beasts. When the filaments are very fine and short, the collection of them is called fur. Wool, also, is a kind of hair. When hair signifies a collection of these animal filaments, it has no plural.
3. Any thing very small or fine; or a very small distance; the breadth of a hair. He judges to a hair, that is, very exactly.
4. A trifling value. It is not worth a hair.
5. Course; order; grain; the hair falling in a certain direction. Not used.
You go against the hair of your profession.
6. Long, straight and distinct filaments on the surface of plants; a species of down or pubescence.
Source: King James Dictionary
Hair
The Hebrews were fully alive to the importance of the hair as an element of personal beauty. Long hair was admired in the case of young men. (2 Samuel 14:26) In times of affliction the hair was altogether cut off. (Isaiah 3:17,24; 15:2; Jeremiah 7:29) Tearing the hair (Ezra 9:3) and letting it go dishevelled were similar tokens of grief. The usual and favorite color of the hair was black, (Solomon 5:11) as is indicated in the comparisons in (Solomon 1:5; 4:1) a similar hue is probably intended by the purple of (Solomon 7:6) Pure white hair was deemed characteristic of the divine Majesty. (Daniel 7:9; Revelation 1:14) The chief beauty of the hair consisted in curls, whether of a natural or an artificial character. With regard to the mode of dressing the hair, we have no very precise information; the terms used are of a general character, as of Jezebel, (2 Kings 9:30) and of Judith, ch. 10:3, and in the New Testament, (1 Timothy 2:9; 1 Peter 3:3) The arrangement of Samson’s hair into seven locks, or more properly braids, (Judges 16:13,19) involves the practice of plaiting, which was also familiar to the Egyptians and Greeks. The locks were probably kept in their place by a fillet, as in Egypt. The Hebrews like other nations of antiquity, anointed the hair profusely with ointments, which were generally compounded of various aromatic ingredients, (Ruth 3:3; 2 Samuel 14:2; Psalms 23:6; 92:10; Ecclesiastes 9:8) more especially on occasions of festivity or hospitality. (Luke 7:46) It appears to have been the custom of the Jews in our Saviour’s time to swear by the hair, (Matthew 5:36) much as the Egyptian women still swear by the side-locks, and the men by their beards.