
1) Ornamental armor piece
Found on
https://www.crosswordclues.com/clue/ailette

plate of armour worn on shoulder
Found on
http://phrontistery.info/a.html

• (n.) A small square shield, formerly worn on the shoulders of knights, -- being the prototype of the modern epaulet.
Found on
http://thinkexist.com/dictionary/meaning/ailette/

(from the article `military technology`) ...this reason, the breastplate was followed shortly by the backplate. From the late 13th century, plate protection spread from the knees and elbows ...
Found on
http://www.britannica.com/eb/a-z/a/32
Ai·lette noun [ French
ailette , dim. of
aile wing, Latin
ala .] A small square shield, formerly worn on the shoulders of knights, -- being the prototype of the modern epaulet.
Fairholt. Found on
http://www.encyclo.co.uk/webster/A/47

In heraldry, an ailette (or emerass) is a small escutcheon which was fixed to the shoulders of armed knights. They were made of steel and introduced during the reign of Edward I, forming the origin of the modern epaulette.
Found on
http://www.probertencyclopaedia.com/browse/UA.HTM

either of two standing pieces of metal or cuir-bouilli, attached to the shoulders as an ornament or as a means of displaying the wearer's arms: used c1275–c1350.
Found on
https://www.infoplease.com/dictionary/ailette
No exact match found.