Noun
Armor for the body, as, the body breastplate and backpiece taken together; -- also, used for the entire suit of the day, including breastplate and backpiece, tasset and headpiece.
The thorax of an insect.
Source: Webster's dictionaryBut who is this who rides in silver white Attire that shames the stars across the night? Helmet and shield and corselet all a-gleam, Like some crusader from a drifting dream Upon a prancing jackass shod with flame- Rise, heralds of the past, bray forth his name. Robert E. Howard