'Plastron' definitions:

Definition of 'plastron'

(from WordNet)
noun
The ornamental front of a woman's bodice or shirt
noun
The front of man's dress shirt
noun
A metal breastplate that was worn under a coat of mail
noun
A large pad worn by a fencer to protect the chest
noun
(zoology) the part of a turtle's shell forming its underside

Definition of 'Plastron'

From: GCIDE
  • Plastron \Plas"tron\, n. [F. plastron breastplate, plastron, LL. plastra a thin plate of metal. See Plaster.]
  • 1. A piece of leather stuffed or padded, worn by fencers to protect the breast. --Dryden. [1913 Webster]
  • 3. (Anc. Armor) An iron breastplate, worn under the hauberk. [1913 Webster]
  • 3. (Anat.) The ventral shield or shell of tortoises and turtles. See Testudinata. [1913 Webster]
  • 4. A trimming for the front of a woman's dress, made of a different material, and narrowing from the shoulders to the waist. [1913 Webster]