A babydoll is a short nightgown or negligee intended as nightwear usually with matching panties. Babydolls are often trimmed with lace, ruffles, bows and ribbons, optionally with spaghetti straps. Sometimes it is made of sheer or translucent fabric like nylon or chiffon or silk.
The term Baby Doll came about from the 1956 movie of that name starring Carroll Baker (best actress nominee). The film opens with Baker lying on her crib (bed) wearing what is now called a Baby Doll. Although somewhat tame by contemporary standards, it was very risqué for the time. In fact, the movie was widely condemned by the Catholic Church.