The plastron (plural: plastrons or plastra) is the nearly flat part of the shell structure of a turtle, what one would call the belly or ventral surface of the shell.

English speakers first borrowed French's word for a breastplate, plastron, as the name for the protective plate worn under a tunic of [chain mail] (/dictionary/chain mail) by knights. In the …

The carapace and plastron are bony structures that usually join one another along each side of the body, creating a rigid skeletal box. This box, composed of bone and cartilage, is retained …

Jul 21, 2025 · The plastron is the flat, bottom portion of a turtle or tortoise’s shell. It serves as the ventral, or underside, connecting to the upper part known as the carapace. This entire shell is …

The plastron is a half jacket that is worn under the fencing jacket to provide an additional layer of protection. The plastron, also known as underarm guard, is compulsory for fencers to wear …

Nov 7, 2025 · 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 …

PLASTRON definition: a piece of plate armor for the upper part of the torso in front. See examples of plastron used in a sentence.

The plastron is the ventral (bottom) part of a turtle or tortoise shell. It provides protection to the organism's underside and houses several key anatomical features.

There are ten meanings listed in OED's entry for the noun plastron, two of which are labelled obsolete. See ‘Meaning & use’ for definitions, usage, and quotation evidence.

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