nightgown
A nightgown, nightie or nightdress is a loosely hanging item of nightwear, today almost exclusively worn by women.
A nightgown may have any neckline, and may have sleeves of any type, or be sleeveless, and any shoulder strap or back style. The length of a nightgown may vary from hip-length to floor-length. A short nightgown can be called a "shortie" or a Babydoll.