chop (v.1)
"to cut with a quick blow," mid-14c., of uncertain origin, 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." Related: Chopped; chopping.
chop (v.2)
"shift quickly," 1530s, earlier "to bargain" (early 15c.), ultimately from Old English ceapian "to bargain" (see cheap); here with a sense of "changing back and forth," probably from common expressions such as to chop and change "barter." To chop logic is recorded from 1570s. Related: Chopped; chopping.
chop (n.)
"act of chopping," mid-14c., from chop (v.1). Meaning "piece cut off" is mid-15c.; specifically "slice of meat" from mid-17c. Sense of "a blow, strike" is from 1550s.