Teddy

A teddy, also called a camiknicker, is a garment which covers the torso and crotch in the one garment. It is similar to a one-piece swimsuit or bodysuit, but is typically looser and more sheer. Most modern teddies are designed for visual and sex appeal, and are lingerie combining the functions of a camisole and panties.

A teddiette is a teddy with detachable garters.
A "sleep romper" is similar in style to the teddy, but with the appearance of shorts.

NSFW Teddy
NSFW Teddiette
NSFW Romper

NSFW Comparison - Left: chemise, center: teddy, right: baby-doll. Only the teddy wraps around the crotch, and the baby-doll is much looser around the hips than the chemise.