Packing Pack"ing, n. 1. The act or process of one who packs. 2. Any material used to pack, fill up, or make close. Specifically (Mach.): A substance or piece used to make a joint impervious; as: (a) A thin layer, or sheet, of yielding or elastic material inserted between the surfaces of a flange joint. (b) The substance in a stuffing box, through which a piston rod slides. (c) A yielding ring, as of metal, which surrounds a piston and maintains a tight fit, as inside a cylinder, etc. 3. (Masonry) Same as Filling. [Rare in the U. S.] 4. A trick; collusion. [Obs.] --Bale. Cherd packing (Bridge Building), the arrangement, side by side, of several parts, as bars, diagonals, a post, etc., on a pin at the bottom of a chord. --Waddell. Packing box, a stuffing box. See under Stuffing. Packing press, a powerful press for baling cotton, wool, hay, etc. Packing ring. See Packing, 2 (c), and Illust. of Piston. Packing sheet. (a) A large cloth for packing goods. (b) A sheet prepared for packing hydropathic patients.