Source : Webster's Revised Unabridged Dictionary (1913)

Packer \Pack"er\, n.
   A ring of packing or a special device to render gas-tight and
   water-tight the space between the tubing and bore of an oil
   well. [U. S.]

Packer \Pack"er\, n.
   A person whose business is to pack things; especially, one
   who packs food for preservation; as, a pork packer.

Source : WordNet®

packer
     n 1: a workman employed to pack things into containers [syn: {bagger},
           {boxer}]
     2: a wholesaler in the meat-packing business [syn: {meat packer}]
     3: a hiker who wears a backpack [syn: {backpacker}]