Source : Webster's Revised Unabridged Dictionary (1913)

Dossier \Dos`sier"\ (d[-o]s`sy[asl]"; E. d[o^]s"s[i^]*[~e]r), n.
   [F., back of a thing, bulging bundle of papers, fr. dos
   back.]
   A bundle containing the papers in reference to some matter.

Source : WordNet®

dossier
     n : a collection of papers containing detailed information about
         a particular person or subject (usually a person's
         record)