A bustier is a form-fitting garment

Form-fitting garment

A form-fitting garment is an article of clothing that tightly follows the contours of the part of the body being covered. There are numerous types of clothing which typically are or which can be made form-fitting. For example, stockings, leggings, tights and socks are usually form-fitting...

 for women, which is traditionally worn as lingerie

Lingerie

Lingerie are fashionable and possibly alluring undergarments.Lingerie usually incorporates one or more flexible, stretchy materials like Lycra, nylon , polyester, satin, lace, silk and sheer fabric which are not typically used in more functional, basic cotton undergarments.The term in the French...

. Its primary purpose is to push up the bust

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...

 by tightening against the upper midriff

Midriff

Midriff is a particular term to denominate the section of the human body between the thorax/chest and the pelvis/hips. It is used as a genteel avoidance of synonymous belly ; as a synonym for waist; and as a name for the area around the diaphragm Midriff is a particular term to denominate the...

 and forcing the breasts up, while gently shaping the waist. Nowadays, it might also be worn as a push-up bra under a low-backed dress, or as a camisole

Camisole

A camisole is a sleeveless undergarment for women, normally extending to the waist. The camisole is usually made of satin, nylon, or cotton.- Historical definition :...

 for outer wear. The bustier can also be worn as a half-slip

Slip (clothing)

Slip is a woman's undergarment worn beneath a dress or skirt to help it hang smoothly and to prevent chafing of the skin from coarse fabrics such as wool...

 under diaphanous upper garments if a bold display of the midriff is not desired.

Bustiers were made popular by Selena Quintanilla.

A bustier resembles a basque

Basque (clothing)

A torsolette is a short corselette, covering the chest to the waist line.The undergarment is similar to a Victorian-era corset, but with less compression of the ribs. The modern-day Torsolette features lace-up or hook-and-eye fastening, as well as boning or vertical seams for structure and support...

, but is shorter.