Definitions for old norse
Random House Webster's College Dictionary
the North Germanic language of medieval Scandinavia.
Ref: Abbr.: ON 3
Origin of Old Norse:
the extinct Germanic language of medieval Scandinavia and Iceland from about to 700 to 1350
The language of Scandinavia before 1400 , the common ancestor of modern Swedish, Danish, Norwegian, Faroese and Icelandic.