The Collaborative International Dictionary of English v.0.48:

shirtwaist \shirtwaist\, Shirt waist \Shirt waist\ [shirt +
   waist; see waist[3], n.]
   1. A woman's blouse resembling a men's shirt in cut and
      style; -- in England called a blouse.
      [Webster 1913 Suppl. +PJC]

   2. a type of woman's dress with a bodice tailored like a
      shirt; -- also called shirt dress, shirtwaist dress,
      and shirtwaister. --[RHUD]
      [PJC]

The Collaborative International Dictionary of English v.0.48:

Blouse \Blouse\ (blouz; F. bl[=oo]z), n. [F. blouse. Of unknown
   origin.]
   A light, loose over-garment, like a smock frock, worn
   especially by workingmen in France; also, a loose coat of any
   material, as the undress uniform coat of the United States
   army.
   [1913 Webster]

WordNet (r) 3.0 (2006):

blouse
    n 1: a top worn by women