gild, guild, lodge, club, society, order - 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"

chapter - a local branch of some fraternity or association; "he joined the Atlanta chapter"

class, social class, socio-economic class - people having the same social or economic status; "the working class"; "an emerging professional class"

brother - a male person who is a fellow member (of a fraternity or religion of other group); "none of his brothers would betray him"

sodalist - a member of a sodality