The Collaborative International Dictionary of English v.0.48:

Hamper \Ham"per\, n. [See Hamper to shackle.]
   1. A shackle; a fetter; anything which impedes. --W. Browne.
      [1913 Webster]

   2. (Naut.) Articles ordinarily indispensable, but in the way
      at certain times. --Ham. Nav. Encyc.
      [1913 Webster]

   Top hamper (Naut.), unnecessary spars and rigging kept
      aloft.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Top-hamper \Top"-ham`per\, n. (Naut.)
   The upper rigging, spars, etc., of a ship. [Written also top
   hamper.]
   [1913 Webster]

         All the ships of the fleet . . . were so encumbered
         with tophamper, so overweighted in proportion to their
         draught of water, that they could bear but little
         canvas, even with smooth seas and light and favorable
         winds.                                   --Motley.
   [1913 Webster]