* gremio: This is the most common and generally accepted translation for a guild, especially in a historical or medieval context. It refers to an association of craftsmen or merchants.
* sindicato: This translates to "union" and is appropriate if the guild is focused on worker's rights and collective bargaining.
* cofradía: This term refers to a brotherhood or sisterhood, often religious in nature, but can sometimes be used for a guild with a strong social or religious aspect.
* asociación: This is a more general term meaning "association" and could be used if the specific nature of the guild isn't important.
To choose the best word, consider what kind of guild you're referring to. For example, a medieval craftsman's guild would be best described as a *gremio*, while a modern-day union of workers might be better described as a *sindicato*.