Corsage refers to the bodice

Bodice

A bodice, historically, is an article of clothing for women, covering the body from the neck to the waist. In modern usage it typically refers to a specific type of upper garment common in Europe during the 16th to the 18th century, or to the upper portion of a modern dress to distinguish it from...

 of a dress. In the 19th century, corsage was a common term for a woman's bodice or jacket.

In modern usage, corsage is often confused with a corset

Corset

A corset is a garment worn to hold and shape the torso into a desired shape for aesthetic or medical purposes...

, but a corset is tighter. A bridal corset is often a corsage.

Originally, a bouquet of flowers

Flower bouquet

A flower bouquet is a collection of flowers in a creative arrangement. There are different kinds including nosegay, crescent, and cascading bouquets. Flower bouquets are often given for special occasions such as birthdays or anniversaries. They are also used extensively in weddings. Traditionally...

, flower bud, or a bow was worn on the corsage between the breast

Breast

The breast is the upper ventral region of the torso of a primate, in left and right sides, which in a female contains the mammary gland that secretes milk used to feed infants.Both men and women develop breasts from the same embryological tissues...

s, hence the name corsage for a cluster of flowers worn on the breast, waist or wrist.

Recently, it is a cluster of flowers given to one's date at a prom

Prom

In the United States and Canada, a prom, short for promenade, is a formal dance, or gathering of high school students. It is typically held near the end of the senior year. It figures greatly in popular culture and is a major event among high school students...

or formal dance to wear on either a dress or a wrist.