Source : Webster's Revised Unabridged Dictionary (1913)

Sandman \Sand"man`\, n.
   A mythical person who makes children sleepy, so that they rub
   their eyes as if there were sand in them.

Source : WordNet®

sandman
     n : an elf in fairy stories who sprinkles sand in children's
         eyes to make them sleepy

Source : Free On-Line Dictionary of Computing

Sandman
     
        The {DoD} requirements that led to {APSE}.