Source : Webster's Revised Unabridged Dictionary (1913)

Quicksand \Quick"sand`\, n.
   Sand easily moved or readily yielding to pressure;
   especially, a deep mass of loose or moving sand mixed with
   water, sometimes found at the mouth of a river or along some
   coasts, and very dangerous, from the difficulty of
   extricating a person who begins sinking into it.

         Life hath quicksands, -- Life hath snares!
                                                  --Longfellow.

Source : WordNet®

quicksand
     n 1: a treacherous situation that tends to entrap and destroy
     2: a pit filled with loose wet sand into which objects are
        sucked down