A herald, or a herald of arms, is an officer of arms, ranking between pursuivant and king of arms. The title is commonly applied more broadly to all officers of arms.
Heralds were originally messengers sent by monarchs or noblemen to convey messages or proclamations—in this sense being the predecessors of modern diplomats.
A tabard is a type of short coat that was commonly worn by men during the late Middle Ages and early modern period in Europe. Generally worn outdoors, the coat was either sleeveless or had short sleeves or shoulder pieces. In its more developed form it was open at the sides, and it could be worn with or without a belt. Though most were ordinary garments, often work clothes, tabards might be emblazoned on the front and back with a coat of arms (livery), and in this form they survive as the distinctive garment of officers of arms.
In modern British usage, the term has been revived for what is known in American English as a cobbler apron: a lightweight open-sided upper overgarment, of similar design to its medieval and heraldic counterpart, worn in particular by workers in the catering, cleaning and healthcare industries as protective clothing, or outdoors by those requiring high-visibility clothing. Tabards may also be worn by percussionists in marching bands in order to protect their uniforms from the straps and rigging used to support the instruments.