The Collaborative International Dictionary of English v.0.48:

Lumpen \Lump"en\, n.
   1. (Politics) same as lumpenproletariat.
      [PJC]

   2. (Zool.) The European eelpout; -- called also lumper.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Lumper \Lump"er\, n. [Cf. Lamper eel.] (Zool.)
   The European eelpout; -- called also lumpen.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Lumper \Lump"er\, n.
   1. One who lumps.
      [1913 Webster]

   2. A laborer who is employed to load or unload vessels when
      in harbor.
      [1913 Webster]

WordNet (r) 3.0 (2006):

lumper
    n 1: a laborer who loads and unloads vessels in a port [syn:
         stevedore, loader, longshoreman, docker,
         dockhand, dock worker, dockworker, dock-walloper,
         lumper]
    2: a taxonomist who classifies organisms into large groups on
       the basis of major characteristics [ant: divider,
       splitter]