"to cut with a quick blow," mid-14c., of uncertain origin, not found in Old English, perhaps from Old North French choper (Old French coper "to cut, cut off," 12c., Modern French couper), from Vulgar Latin *cuppare "to behead," from a root meaning "head," but influenced in Old French by couper "to strike" (see coup). There are similar words in continental Germanic (Dutch, German kappen "to chop, cut").
Related: Chopped; chopping. Chopping-block "block of wood on which anything (especially food) is laid to be chopped" is from 1703.