Sorority :  (noun)

1: a social club for female undergraduates

affiliation, alignment, alliance, amalgamation, association, boon companionship, brotherhood, brotherliness, cahoots, chumship, club, coadunation, coalescence, coalition, colleagueship, collegialism, collegiality, combination, community of interest, companionship, comradeship, confederacy, confederation, confraternity, confrerie, consolidation, consortship, copartnership, copartnery, country club, esprit de corps, federation, fellowship, fraternal order, fraternalism, fraternity, fraternization, freemasonry, fusion, guild, hookup, inclusion, incorporation, integration, league, merger, order, partnership, secret society, sisterhood, sisterliness, society, sodality, tie-in, tie-up, unification, union,