Noun

1. The point that stands backward in an arrow, fishhook, etc., to prevent it from being easily extracted. Hence: Anything which stands out with a sharp point obliquely or crosswise to something else.
   • Roger Ascham:

     Having two barbs or points.

2. A beard, or that which resembles it, or grows in the place of it.
3. (Corrupt) Armor for a horse, corrupted from bard.
   • 1786, Francis Grose, A Treatise on Ancient Armour and Weapons, page 29:

     The defensive armor with the horses of the ancient knights ... These are frequently, though improperly, stiled barbs.

4. One of the side branches of a feather, which collectively constitute the vane.
5. Several species of freshwater fish of the Cyprinid family.
6. A southern name for the kingfishes of the eastern and southeastern coasts of the United States; -- also improperly called whiting.
7. A hair or bristle ending in a double hook.
8. A blackish or dun variety of the pigeon, originally brought from Barbary.
9. A muffler, worn by nuns and mourners.
10. Paps, or little projections, of the mucous membrane, which mark the opening of the submaxillary glands under the tongue in horses and cattle. The name is mostly applied when the barbs are inflamed and swollen. [Written also barbel and barble.]
    • Izaak Walton:

      The barbel, so called by reason of his barbs, or wattles in his mouth.

11. A bit for a horse.

Verb

1. To furnish with barbs, or with that which will hold or hurt like barbs, as an arrow, fishhook, spear, etc.

   But rattling storm of arrows barbed with fire. — Milton.

2. (Corrupt) To cover a horse in armor, corrupted from bard.
   • 1592, William Shakespeare, Richard III, Act I, Scene I, line 10:

     And now, in stead of mounting barbed steeds To fright the souls of fearful adversaries, He capers nimbly in a lady's chamber...

3. To shave or dress the beard of.
4. To clip; to mow.

Noun

1. The Barbary horse, a superior breed introduces from Barbary into Spain by the Moors.