n. The relationship of a brother; the condition of being a brother or of being brothers; brotherhood.n. Hence That mutual interest and affection which is characteristic of the fraternal relation; brotherly regard and sympathy for others, regardless of relationship by blood; brotherhood in general.n. A body of men associated by some natural tie, as of common interest or character, of common business or profession, or by some formal tie, as of organization for religious or social purposes; a company; a brotherhood; a society: as, a fraternity of monks; a college fraternity.n. Specifically, in the Roman Catholic Church, an organization of laymen for pious or charitable purposes, as the special worship of Christ, the honor of the Virgin Mary or of particular saints, the care of the distressed, sick, or dead, etc. Also called confraternity, gild, or sodality.