English

The plastron (underside) of a Cann's snake-neck turtle (Chelodina canni)

A fencing plastron

Noun

plastron ‎(plural plastrons)

1. The nearly flat part of the shell structure of a tortoise or other animal, similar in composition to the carapace.
2. (fencing) A half-jacket worn under the jacket for padding or for safety.
3. An ornamental front panel on a woman's bodice.
   • 1942, Rebecca West, Black Lamb and Grey Falcon, Canongate 2006, p. 784,

     I bought here a wedding dress perhaps twenty or thirty years old [...] a sequin plastron to be worn over the womb as a feminine equivalent to a cod-piece, and a gauze veil embroidered in purple and gold.

4. A film of air trapped by specialized hairs against the body of an aquatic insect, and which acts as an external gill.

   The plastron of a diving beetle is not directly a source of oxygen, but acts as a gill, acquiring oxygen from the surrounding water.

   • 2013, Jill Lancaster, Barbara J. Downes, Aquatic Entomology, page 45,

     Total independence of atmospheric air is possible only if insects have a permanent gas store or incompressible gas gill, called a plastron. Unlike compressible gas stores, the volume of a plastron remains constant and it is incompressible.

   • 2013, Jon F. Harrison, Lutz T. Wasserthal (revisions & updates), 17: Gaseous Exchange, R. F. Chapman, Stephen J. Simpson (editor), Angela E. Douglas (editor), The Insects: Structure and Function, 5th Edition, page 535,

     The plastrons of other insects are generally less efficient than that of Aphelocheirus as they have a less dense hair pile from which the air is more readily displaced.

Translations

Esperanto

Noun

plastron

1. accusative of plastro

French

Etymology

Borrowing from Italian piastrone.

Noun

plastron m ‎(plural plastrons)

1. breastplate (piece of armour)
2. (fencing) plastron
3. chest pad; chest protection; chestguard
4. (zoology) plastron (part of a turtle's shell)
5. shirt front; the front of a shirt
6. plastron (ornamental front part of a bodice)
7. (zoology) breast (front part of certain birds)

Derived terms

• plastronnant
• plastronné
• plastronner