Source : Webster's Revised Unabridged Dictionary (1913)

Duffel bag \Duffel bag\
   A sack to hold miscellaneous articles, as tools, supplies, or
   the like.

Source : WordNet®

duffel bag
     n : a large cylindrical bag of heavy cloth; for carrying
         personal belongings [syn: {duffle bag}, {duffel}, {duffle}]