1206, from O.N.Fr. planke
) "plank, slab, little wooden bridge," from L.L. planca
"broad slab, board," related to phalanga
"pole to carry burdens," from Gk. phalange
). Technically, timber sawed to measure 2 to 6 inches thick, 9 inches or more wide, and 8 feet or more long. Political sense of "item of a party platform" is U.S. coinage from 1848. To walk the plank,
supposedly a pirate punishment, is first attested 1822 in Scott.