Source : Webster's Revised Unabridged Dictionary (1913)

Loader \Load"er\, n.
   One who, or that which, loads; a mechanical contrivance for
   loading, as a gun.

Source : WordNet®

loader
     n 1: a laborer who loads and unloads vessels in a port [syn: {stevedore},
           {longshoreman}, {docker}, {dockhand}, {dock worker}, {dock-walloper},
           {lumper}]
     2: an attendant who loads guns for someone shooting game