breastpin 
noun archaic
A small brooch or badge worn on the chest, typically to fasten a garment.Against the strict rules of your order, you use an arc and compass breastpin....
- Cameo breastpins were a favorite with many, while nearly every girl had her ears pierced for earrings.
- A New York company used several car loads of Cannel yearly in making finger rings, breastpins and buttons.