The Collaborative International Dictionary of English v.0.48:

Saga \Sa"ga\ (s[=a]"g[.a]), n.; pl. Sagas (-g[.a]z). [Icel.,
   akin to E. saw a saying. See Say, and cf. Saw.]
   A Scandinavian legend, or heroic or mythic tradition, among
   the Norsemen and kindred people; a northern European popular
   historical or religious tale of olden time.
   [1913 Webster]

         And then the blue-eyed Norseman told
         A saga of the days of old.               --Longfellow.
   [1913 Webster]