The Collaborative International Dictionary of English v.0.48:

Sachet \Sa`chet"\, n. [F., dim. of sac. See Sac.]
   A scent bag, or perfume cushion, to be laid among
   handkerchiefs, garments, etc., to perfume them.
   [1913 Webster]

WordNet (r) 3.0 (2006):

sachet
    n 1: a small soft bag containing perfumed powder; used to
         perfume items in a drawer or chest