surcoat

noun2

1. •
   (historical) A loose sleeveless garment worn over a suit of armor, sometimes colored or embroidered with the wearer's coat of arms.

   • The Lord mayor and sheriff ride in their armour with surcoats of crimson. — 2020
2. •
   (historical) An overgarment worn over a woman's gown; a kind of short robe worn over the tunic at the close of the 11th century.

   • She wore a short surcoat of scarlet, cut low around the shoulders, sleeveless, reaching just below her hips, like the tabards worn by medieval heralds. Over it she wore a laced-edged cotta. — 1965