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early 15c., "suitable for plowing" (as opposed to pasture- or wood-land), from Old French arable (12c.), from Latin arabilis, from arare "to plow," from PIE *are- "to plow" (cf. Greek aroun, Old Church Slavonic orja, Lithuanian ariu "to plow;" Gothic arjan, Old English erian, Middle Irish airim, Welsh arddu "to plow;" Old Norse arþr "a plow"). Replaced by late 18c. native erable, from Old English erian "to plow," from the same PIE source.