grand guard

noun1

1. •
   (historical) A piece of plate armor protecting one shoulder, side of the chest, and side of the neck (typically the left), during jousting, augmenting or replacing a pauldron.

   • […] their horses, their lances, and every thing appertaining to the joust, that they might be ready on the day […] the rich bardes, the pleasant trapgardes, the grand guards, […] — 1846