Definition of plastron

• n. - A piece of leather stuffed or padded, worn by fencers to protect the breast.
• n. - An iron breastplate, worn under the hauberk.
• n. - The ventral shield or shell of tortoises and turtles. See Testudinata.
• n. - A trimming for the front of a woman's dress, made of a different material, and narrowing from the shoulders to the waist.