From The Collaborative International Dictionary of English v.0.48:
Plank \Plank\, v. t. [imp. & p. p. Planked; p. pr. & vb. n. Planking.] 1. To cover or lay with planks; as, to plank a floor or a ship. "Planked with pine." --Dryden. [1913 Webster]
2. To lay down, as on a plank or table; to stake or pay cash; as, to plank money in a wager. [Colloq. U.S.] [1913 Webster]
3. To harden, as hat bodies, by felting. [1913 Webster]
4. (Wooden Manuf.) To splice together the ends of slivers of wool, for subsequent drawing. [1913 Webster]
Planked shad, shad split open, fastened to a plank, and roasted before a wood fire. [1913 Webster]
From The Collaborative International Dictionary of English v.0.48:
Planking \Plank"ing\, n. 1. The act of laying planks; also, planks, collectively; a series of planks in place, as the wooden covering of the frame of a vessel. [1913 Webster]
2. The act of splicing slivers. See Plank, v. t., 4. [1913 Webster]