underskirt vs waistband

underskirt

noun
  • A skirt worn underneath another skirt; a petticoat. 

  • An under layer of a multi-layer gown over which outer skirts are draped. 

waistband

noun
  • A band of fabric encircling the waist, especially a part of a pair of pants or a skirt. 

How often have the words underskirt and waistband occurred in a corpus of books? (source: Google Ngram Viewer )