ailette

The ailette was a component of thirteenth century knightly armour. Usually made of leather (sometimes of plate or parchment), ailettes attached to the shoulders by means of silk or leather cord. Ailettes were usually flat and nearly rectangular in shape, and usually decorated with heraldic designs.The purpose of ailettes is a matter of disagreement amongst scholars. Some, such as Charles ffoulkes, claim that they enhanced protection to the neck, while others, like Ewart Oakeshott, argue that they were used primarily for decorative and heraldic reasons.
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n. fin, organ attached to various parts of a fish's body

(n.)
A small square shield, formerly worn on the shoulders of knights, -- being the prototype of the modern epaulet.