Shirt waist \Shirt waist\ A belted waist resembling a shirt in plainness of cut and style, worn by women or children; -- in England called a blouse.

Source: Webster's Revised Unabridged Dictionary (1913)
 

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.

Source: Webster's Revised Unabridged Dictionary (1913)