guild

noun4

1. •
   A group or association mainly of tradespeople made up of merchants, craftspeople, or artisans, particularly in the Middle Ages, established to oversee and protect their specific commercial interests and to provide mutual aid.

   • The swinging of its censers, the silence of its members / Oh, the Guild of Mute Assassins — 2003
2. •
   A corporation.
3. •
   An organized group of players who regularly play together in a multiplayer game.
4. •
   A group of diverse species that share common characteristics or habits.