Definition of guilds:
(n) :
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.
(n) :
(video games) An organized group of players who regularly play together in a multiplayer game.
(n) :
A corporation.
(n) :
(ecology) A group of diverse species that share common characteristics or habits.
(n) :
A surname.