ETYM French blouse. Of unknown origin.
A top worn by women.
A shirtlike garment worn by women. It can be plain, but tends to be more highly decorated than a man's shirt, with embroidery and differing lapel shapes and sizes. It is made of cotton or any light fabric.
The term is also used to refer to the waist-length belted jacket worn by soldiers.

Tto fall in a fold
To cause to blouse