Source : Webster's Revised Unabridged Dictionary (1913)

Ris \Ris\, n. [AS. hr[=i]s; akin to D. rils, G. reis, OHG.
   hr[=i]s.]
   A bough or branch; a twig. [Obs.]

         As white as is the blossom upon the ris. --Chaucer.