stomacher

Short definition from Wiktionary

Noun

1. 1
   A type of men's waistcoat.
2. 2
   An ornamental cloth, often embellished with embroidery or jewelry, worn over the chest by women beneath their bodices or by men and women as the central part of an open shirt, blouse, or jacket.
3. 3
   A similar item of mail worn over and protecting the stomach.
4. 4
   A blow to the stomach.