The Collaborative International Dictionary of English v.0.48:

futharc \fu"tharc\, futhorc \fu"thorc\, futhork \fu"thork\n.
   1. [From the sounds of the first five letters.] The Runic
      alphabet; -- so called from the first six letters f, u,
      [thorn] (th), o (or a), r, c (=k). See rune. [Also
      spelled futhark]
      [Webster 1913 Suppl.]

   Note: The spelling futharc represents most accurately the
         original values of these six Runic letters.
         [Webster 1913 Suppl.]

   Note: The name is derived from the sounds of the first five
         letters of the runic alphabet, f, u, th, o, r, and c.
         The vowel sound of the fourth letter corresponded more
         closely to a in the earlier versions used in
         Scandinavian countries, and the earlier alphabet is
         therefore referred to as the futharc or futhark. The
         fifth rune had a sound like that of k, and in the
         Danish futhark the fifth character is that
         transliterated as k. Thus the runic alphabet is also
         called the futhork or futhark. The third rune had a
         sound and form resembling that of the Anglo-Saxon
         thorn, which represented the th sound at the beginning
         of the word thorn. The origins of the runic alphabet
         are obscure, but the earliest forms may have been
         invented around the second century A.D. in eastern
         Europe. The forms of some of the letters show a
         relation to the Latin or Greek alphabets, and the
         futhorc was presumably in part an adaptation of those
         alphabets to the sound of the Germanic tongues. An
         inscription of the futhark itself, an ordered list of
         the runes, was found on an object dated as early as the
         fifth century A.D. The Scandinavian futharc had 16
         runes, but the futhorc used in Anglo-Saxon England had
         31. The futhark was mostly used for writing on wood,
         for which reason the runes were comprised of only
         vertical and diagonal strokes. The degree of widespread
         use of the futharc is not known but it was probably
         used mostly for short messages or inscriptions on
         objects. Fewer than 10,000 runic inscriptions, both on
         wood and stone, have been found. The number and forms
         of some of the runes varied over time and locality.
         --R. I. Page, "Runes".
         [PJC]

               The letters are called Runes and the alphabet
               bears the name Futhorc from the first six
               letters.                           --I. Taylor.
         [Webster 1913 Suppl.]