Noun six nations has 1 sense

1. Iroquois League, League of Iroquois, Five Nations, Six Nations - 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)
   --₁ is a kind of league
   

A rugby union tournament played annually between six European nations: England, Scotland, Wales, Ireland, France, and Italy.

Sample Sentence: The Six Nations is known for its intense rugby matches and electrifying atmosphere.

A reference to a group of indigenous nations formed by the Haudenosaunee Confederacy, including the Mohawk, Oneida, Onondaga, Cayuga, Seneca, and Tuscarora nations in North America.

Sample Sentence: The Six Nations confederacy has a rich cultural heritage and a strong connection to their ancestral lands.