Source : Webster's Revised Unabridged Dictionary (1913)

Sunbeam \Sun"beam`\, n. [AS. sunnebeam.]
   A beam or ray of the sun. ``Evening sunbeams.'' --Keble.

         Thither came Uriel, gliding through the even On a
         sunbeam.                                 --Milton.

Source : WordNet®

sunbeam
     n : a ray of sunlight [syn: {sunray}]