From The Collaborative International Dictionary of English v.0.48:
Plank \Plank\, n. [OE. planke, OF. planque, planche, F. planche,
fr. L. planca; cf. Gr. ?, ?, anything flat and broad. Cf.
Planch.]
1. A broad piece of sawed timber, differing from a board only
in being thicker. See Board.
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2. Fig.: That which supports or upholds, as a board does a
swimmer.
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His charity is a better plank than the faith of an
intolerant and bitter-minded bigot. --Southey.
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3. One of the separate articles in a declaration of the
principles of a party or cause; as, a plank in the
national platform. [Cant]
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Plank road, or Plank way, a road surface formed of
planks. [U.S.]
To walk the plank, to walk along a plank laid across the
bulwark of a ship, until one overbalances it and falls
into the sea; -- a method of disposing of captives
practiced by pirates.
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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.
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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.]
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3. To harden, as hat bodies, by felting.
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4. (Wooden Manuf.) To splice together the ends of slivers of
wool, for subsequent drawing.
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Planked shad, shad split open, fastened to a plank, and
roasted before a wood fire.
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