PLASTRON
plastron
(noun) (zoology) the part of a turtle’s shell forming its underside
plastron
(noun) a large pad worn by a fencer to protect the chest
plastron
(noun) a metal breastplate that was worn under a coat of mail
plastron
(noun) the front of man’s dress shirt
plastron
(noun) the ornamental front of a woman’s bodice or shirt
Source: WordNet® 3.1
Etymology
Noun
plastron (plural plastrons)
The nearly flat part of the shell structure of a tortoise or other animal, similar in composition to the carapace.
(fencing) A half-jacket worn under the jacket for padding or for safety.
A man's shirt-bosom.
An ornamental front panel on a woman's bodice.
A breastplate.
A film of air trapped by specialized hairs against the body of an aquatic insect, and which acts as an external gill.
Source: Wiktionary
Plas"tron, n. Etym: [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.
3. (Anc. Armor)
Definition: An iron breastplate, worn under the hauberk.
3. (Anat.)
Definition: The ventral shield or shell of tortoises and turtles. See
Testudinata.
4. A trimming for the front of a woman's dress, made of a different
material, and narrowing from the shoulders to the waist.
Source: Webster’s Unabridged Dictionary 1913 Edition