The Collaborative International Dictionary of English v.0.48:

Northman \North"man\ (n[^o]rth"man), prop. n.; pl. Northmen.
   [AS. nor[eth]man. See North, and Man, and cf. Norman.]
   One of the inhabitants of the north of Europe; esp., one of
   the ancient Scandinavians; a Norseman.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Northman
    n 1: an inhabitant of Scandinavia [syn: Scandinavian, Norse,
         Northman]