carp: [14] and carp ‘criticize’ [13] are distinct words in English. The former comes from medieval Latin carpa, probably via Old French carpe, but the word is probably ultimately of Germanic origin. The verb, which originally simply meant ‘talk’, was a borrowing from Old Norse karpa. The present-day sense ‘criticize’ did not develop until the 16th century, probably under the influence of Latin carpere ‘pluck’ (related to English harvest), which had the metaphorical meaning ‘slander’. => harvest
carp (n.)
type of freshwater fish, late 14c., from Old French carpe "carp" (13c.) and directly from Vulgar Latin carpa (source also of Italian carpa, Spanish carpa), from a Germanic source (compare Middle Dutch carpe, Dutch karper, Old High German karpfo, German Karpfen "carp"); possibly the immediate source is Gothic *karpa. A Danube fish (hence the proposed East Germanic origin of its name), introduced in English ponds 14c. Lithuanian karpis, Russian karp are Germanic loan words.
carp (v.)
"complain," early 13c., originally "to talk," from Old Norse karpa "to brag," which is of unknown origin; meaning turned toward "find fault with" (late 14c.), probably by influence of Latin carpere "to slander, revile," literally "to pluck" (see harvest (n.)). Related: Carped; carping.