The Collaborative International Dictionary of English v.0.48:
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
(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,
Packing ring. See Packing, 2
(c), and Illust. of Piston.
(a) A large cloth for packing goods.
(b) A sheet prepared for packing hydropathic patients.