Meaning of chin strap

chin' strap"

Pronunciation: [key]
  1. a strap attached to a hat for passing under the chin of the wearer.
  2. a strap to support the chin in cosmetic facial treatment.
  3. a strap on a bridle or halter that joins the throatlatch and noseband.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.