plastron

plas·tron

noun \ˈplas-trən\

Definition of PLASTRON

1

a : a metal breastplate formerly worn under the hauberk b : a quilted pad worn in fencing to protect the chest, waist, and the side on which the weapon is held

2

: the ventral part of the shell of a tortoise or turtle consisting typically of nine symmetrically placed bones overlaid by horny plates

3

a : a trimming like a bib for a woman's dress b : dickey 1a

4

: a thin film of air held by water-repellent hairs of some aquatic insects

Origin of PLASTRON

Middle French, from Old Italian piastrone, augmentative of piastra thin metal plate — more at piastre

First Known Use: circa 1507