Meaning

noun a stout length of sawn timber; made in a wide variety of sizes and used for many purposes

noun an endorsed policy in the platform of a political party

verb cover with planks

originFrom Middle English plank, planke, borrowed from Old French planke, Old Northern French planque (compare French planche, from Old French planche), from Vulgar Latin planca, from palanca, from Latin phalanga. The Latin term derives from the Ancient Greek φάλαγξ (phálanx), so it is thus a doublet of phalange and phalanx. Compare also the doublets planch, planche, and plancha, borrowed later from…

Etymology from Wiktionary, CC BY-SA 3.0