fraternity

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A body of people associated for a common purpose or interest, such as a guild.
2. n. A group of people joined by similar backgrounds, occupations, interests, or tastes: the fraternity of bird watchers.
3. n. A chiefly social organization of men students at a college or university, usually designated by Greek letters.
4. n. Roman Catholic Church A sodality.
5. n. The quality or condition of being brothers; brotherliness.

Century Dictionary and Cyclopedia

1. n. The relationship of a brother; the condition of being a brother or of being brothers; brotherhood.
2. 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.
3. 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.
4. 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. Synonyms and Association, circle, sodality, league, clan.

Wiktionary

1. n. The quality of being brothers; brotherhood
2. n. A group of people associated for a common purpose.
3. n. US A social organization of male students at a college or university; usually identified by Greek letters.

GNU Webster's 1913

1. n. The state or quality of being fraternal or brotherly; brotherhood.
2. n. A body of men associated for their common interest, business, or pleasure; a company; a brotherhood; a society; in the Roman Catholic Church, an association for special religious purposes, for relieving the sick and destitute, etc.
3. n. Men of the same class, profession, occupation, character, or tastes.
4. n. A social club for male college undergraduates. They often have secret initiation rites, and are named by the use of two or three Greek letters. The corresponding association for women students is called a sorority.

WordNet 3.0

1. n. a social club for male undergraduates
2. n. people engaged in a particular occupation