plastron

kovitettu paidanrinnus

vatsakilpi

rintahaarniska

rintasuojus The nearly flat part of the shell structure of a tortoise or other animal, similar in composition to the carapace.
puhekieltä A half-jacket worn under the jacket for padding or for safety.
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.

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

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.

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.