phratry
noun
phra·try ˈfrā-trē 
plural phratries
1
: a kinship group forming a subdivision of a Greek phyle
2
: a tribal subdivision
specifically : an exogamous group typically comprising several totemic clans
Word History
Etymology
Greek phratria, from phratēr member of the same clan, member of a phratry — more at brother
First Known Use
1833, in the meaning defined at sense 1