Synonyms for Five Nations (same or very similar meaning)
WordNet sense 1 (a league of Iroquois tribes including originally the Mohawk, Oneida, Onondaga, Cayuga and Seneca (the Five Nations); after 1722 they were joined by the Tuscarora (the Six Nations)):
Iroquois League, League of Iroquois, Six Nations
From the ODE community, based on WordNet
add/edit