More commonly spelled osnaburg, but also osnabrig, oznaburg, etc. (I chose this spelling because that's how it's spelled in the primary source I copied the list from.) A heavy, coarse cloth. In eighteenth-century America, it was used mostly for rough work clothing, such as that worn by laborers, soldiers, and enslaved people.
n. As a mass noun: a kind of coarse linen (and later cotton) cloth originally made at Osnabrück, used esp. for making rough hard-wearing clothing, or for furnishings, sacks, tents, etc. As a count noun (usu. in pl., sometimes treated as sing.): a quantity of this; (also) an item or items made of such cloth, esp. (formerly) clothing given to servants or slaves.