Paillasse

from WordNet (r) 3.0 (2006)

paillasse
    n 1: mattress consisting of a thin pad filled with straw or
         sawdust [syn: {paillasse}, {palliasse}]

from The Collaborative International Dictionary of English v.0.48

Paillasse \Pail*lasse"\ (?; F. ?), n. [F., fr. paille straw. See
   {Pallet} a bed.]
   An under bed or mattress of straw. [Written also
   {palliasse}.]
   [1913 Webster]