BARB. (I) A term used of the folds of mucous membrane under the tongue of horses and cattle, and of a disease affecting that part, of the wattles round the mouth of the barbel, of the backward turned points of an arrow and of the piece of folded linen worn over the neck by nuns (Lat. barba, a beard) . A name applied to a breed of horses imported into Spain from Barbary (Fr. barbe, meaning "from Barbary") and to a breed of pigeons.