The Collaborative International Dictionary of English v.0.48:

Algonquin \Al*gon"quin\, Algonkin \Al*gon"kin\, prop. n.
   One of a widely spread family of Indians, including many
   distinct tribes, which formerly occupied most of the northern
   and eastern part of North America. The name was originally
   applied to a group of Indian tribes north of the River St.
   Lawrence.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Algonkin
    n 1: a member of a North American Indian people in the Ottawa
         river valley of Ontario and Quebec [syn: Algonkian,
         Algonkin]
    2: the Algonquian language spoken by the Algonkian [syn:
       Algonkian, Algonkin]