n.
Pronunciation: ' bres(t)- ˌ pl ā t
Function: noun
Date: 14th century
1 : a usually metal plate worn as defensive armor for the breast ― see ARMOR illustration
2 : a vestment worn in ancient times by a Jewish high priest and set with 12 gems bearing the names of the tribes of Israel
3 : a piece against which a worker's breast is pressed in operating a tool (as a breast drill)