underbust

From under- +‎ bust.

• Audio (US):

  (file)

underbust (not comparable)

1. (clothing) Below the bust.

• underboob

underbust (plural underbusts)

1. A corset that begins just under the breasts and extends down to the hips.
2. (clothing) The circumference of a woman's chest, measured under the breasts.
   • 2015 April 14, Alison Freer, How to Get Dressed: A Costume Designer's Secrets for Making Your Clothes Look, Fit, and Feel Amazing, Ten Speed Press, →ISBN:

     You can measure your underbust and overbust to get an idea of bra size, but it's still just a guideline.