According to the "Oxford English Dictionary", in current British English, a petticoat is "a light loose undergarment ... hanging from the shoulders or waist". In modern American usage, "petticoat" refers only to a garment hanging from the waist. They are most often made of cotton, silk or tulle. Without petticoats, skirts of the 1950s would not have the floof they were known for. In historical contexts (sixteenth to mid-nineteenth centuries), "petticoat" refers to any separate skirt worn with a gown, bedgown, bodice or jacket; these petticoats are not, strictly speaking, underwear, as they were made to be seen. In both historical and modern contexts, "petticoat" refers to skirt-like undergarments worn for warmth or to give the skirt or dress the desired attractive shape.