Definition of Fraternity
A body of persons associated for their common interest, business or pleasure. In American colleges, a student organization, either a nationally chartered society comprising many affiliated chapters or a single chapter in one institution, formed chiefly to promote friendship and welfare among the members, and usually having secret rites and a name consisting of Greek letters. Woman’s Club of Little Falls v. Township of Little Falls, 20 N.J.Misc. 278, 26 A.2d 739, 741.
That's the definition of Fraternity in Black's Law Dictionary 6th Edition. Courtesy of Cekhukum.com.