Definition of "step-in"

step-in

noun
plural step-ins
1. (also in plural) An item of clothing which one steps into to put on; specifically, women's panties.
  Quotations
  ‘Doc got that step-in in Memphis,’ the third said. ‘Off a damn whore.’
  1931, William Faulkner, Sanctuary, Vintage, published 1993, page 46
  One of the girls hoisted her skirt suddenly, pulled and ripped at her pink step-ins and tore them to a sizeable flag; then, screaming "Ben! Ben!" she waved it wildly.
  1934, F[rancis] Scott Fitzgerald, Tender is the Night: A Romance, New York, N.Y.: Charles Scribner’s Sons; republished as chapter VII, in Malcolm Cowley, editor, Tender is the Night: A Romance [...] With the Author’s Final Revisions, New York, N.Y.: Charles Scribner’s Sons, 1951, book V (The Way Home: 1929–1930), page 315