Meaning of underwaist

un•der•waist

Pronunciation: (un'dur-wāst"), [key]
— n.
  1. a blouse worn under another.
  2. such a blouse to which other undergarments are pinned or buttoned, worn by infants and small children.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.