guild

n. professional association; association for mutual aid and protection, fellowship, union, brotherhood

A guild is an association of craftspeople in a particular trade. The earliest guilds are believed to have been formed in India circa 3800 BC, and though they are not as commonplace as they were a few centuries ago, many guilds continue to flourish around the world today. Guilds are less common now than many years ago.
See more at Wikipedia.org...

Noun
1. a formal association of people with similar interests; "he joined a golf club"; "they formed a small lunch society"; "men from the fraternal order will staff the soup kitchen today"
(synonym) club, society, gild, lodge, order
(hypernym) association
(hyponym) athenaeum, atheneum
(member-meronym) club member

(v. t.)
An association of men belonging to the same class, or engaged in kindred pursuits, formed for mutual aid and protection; a business fraternity or corporation; as, the Stationers' Guild; the Ironmongers' Guild. They were originally licensed by the government, and endowed with special privileges and authority.
  

(v. t.)
A religious association or society, organized for charitable purposes or for assistance in parish work.
  

(v. t.)
A guildhall.
  

Professional, mercantile or craft association formed to maintain standards and support its members. Guilds formed the center of town life; the guilds grew in power and prestige, frequently forming monopolies in their area of expertise.