Mas·sa·chu·sett also Mas·sa·chu·set 
(măs′ə-chsĭt, -zĭt)
(măs′ə-chsĭt, -zĭt)n. pl. Massachusett or Mas·sa·chu·setts also Massachuset or Mas·sa·chu·sets
1. A member of a Native American people formerly located along Massachusetts Bay from Plymouth north to Salem. Reduced by epidemics, the Massachusett ceased to exist as a people during the 1600s.
2. The Algonquian language of the Massachusett.
[From the Massachusett name of Great Blue Hill south of Boston.]