What is the meaning of Stomacher?

A type of men's waistcoat.

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.

A similar item of mail worn over and protecting the stomach.

A blow to the stomach.

first-person singular present active subjunctive of stomachor

Alternative form of stomakere

Source: wiktionary.org