The Collaborative International Dictionary of English v.0.48:

Satchel \Satch"el\n. [OF. sachel, fr. L. saccellus, dim. of
   saccus. See Sack a bag.]
   A little sack or bag for carrying papers, books, or small
   articles of wearing apparel; a hand bag. [Spelled also
   sachel.]
   [1913 Webster]

         The whining schoolboy with his satchel.  --Shak.
   [1913 Webster]

WordNet (r) 3.0 (2006):

satchel
    n 1: luggage consisting of a small case with a flat bottom and
         (usually) a shoulder strap