Meaning of iron-jawed

i•ron-jawed

Pronunciation: (ī'urn-jôd'), [key]
— adj.
  1. having a jaw of or like iron: an iron-jawed press; an iron-jawed fighter.
  2. fiercely determined: an iron-jawed will.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.