Dakotas \Da*ko"tas\, n. pl.; sing. {Dacota}. (Ethnol.) An extensive race or stock of Indians, including many tribes, mostly dwelling west of the Mississippi River; -- also, in part, called {Sioux}. [Written also {Dacotahs}.] Dacotahs \Da*co"tahs\, n. pl.; sing. {Dacotan}. (Ethnol.) Same as {Dacotas}. --Longfellow.