A corselet or corselette is type of foundation garment which is a brassiere and girdle in one. It will sometimes have lace in front or in the back. The name is a taken from the word corset with the diminutive "-ette".
It is also the name of a piece of body armor for the torso, and it usually consists of a breastplate and back piece.
The corselette began to replace the corset in 1914 as a substitute for wearing two separate pieces, such as a corset and a brassiere or a girdle and a brassiere.
The bust uplift cups were first used in 1933, but came to common use in 1943.
The original merry widow foundation garment was also a corselette that incorporated slim panels of black elastic yarn net. A heavy-duty zipper was inserted behind a velvet-backed hook-and-eye flange, and the whole garment was lined with nylon voile. Nine long spiral wires were cased in black satin.
Lana Turner is quoted as having said, "I am telling you, the merry widow was designed by a man. A woman would never do that to another woman."
To this day, "merry widow" is the generic term for a corselette bra in the United States. This type of lingerie is also known as a torsolette, and is used in bridal lingerie, similar to the bustier.