The Collaborative International Dictionary
Buff \Buff\, a.
Made of buff leather.
--Goldsmith.-
Of the color of buff.
Buff coat, a close, military outer garment, with short sleeves, and laced tightly over the chest, made of buffalo skin, or other thick and elastic material, worn by soldiers in the 17th century as a defensive covering.
Buff jerkin, originally, a leather waistcoat; afterward, one of cloth of a buff color. [Obs.]
--Nares.Buff stick (Mech.), a strip of wood covered with buff leather, used in polishing.
Wikipedia
The European buff coat (the term deriving from the ox or buffalo hide from which it was commonly made and its yellowish colour) was an item of leather clothing worn by cavalry and officers during the 17th century, it also saw limited use by some infantry. It was often worn under armour. It was derived from the simple leather jerkins worn by huntsmen and soldiers during the Tudor period, these in turn deriving from the arming doublet worn under full plate armour.
Usage examples of "buff coat".
Thomas lay unconscious on the bed, still wearing the doublet and bloodstained buff coat from the battle.
Armor chafed that wound, so the king went into battle protected only by his buff coat and the Will of his God.
The plain buff coat he wore followed it, and the scabbard of his sword.
Mud had generously splashed his breeches and plain buff coat, and his neckcloth was crumpled and limp.
He was dressed in a plain buff coat, with no attempt at a seafaring appearance, but he came up the side like a good 'un, moving his bulk with a strong, easy agility, judging the roll just so.
He was dressed in a plain buff coat, with no attempt at a seafaring appearance, but he came up the side like a good ‘.
His mostly gray hair was windblown, his square face and worn buff coat dusty.
At last she trotted on, her buff coat melting into the vegetation.
He was dressed for riding, with buff coat and buckskin breeches, and shining top boots.
Heinrich swayed briefly, and raised his hands away from his leather buff coat, now only loosely tied in the front.