packsaddle vs saddlebag

packsaddle

noun
  • A saddle designed to secure and carry goods on the back of an animal. 

saddlebag

noun
  • A covered pouch, usually one of a pair, laid across the back of a horse, donkey, or mule behind its saddle, or hanging over the rear wheel of a bicycle or motorcycle; often made of leather or (on a bicycle or motorcycle) a rigid material. 

  • Loose fatty flesh on a person's upper thighs or buttocks, that hangs like saddlebags. 

  • A style of house with two rooms separated by a small hall and open space. 

How often have the words packsaddle and saddlebag occurred in a corpus of books? (source: Google Ngram Viewer )