Meaning

noun a person who is gullible and easy to take advantage of

originOrigin uncertain; probably a blend of chunk and lump or stump, or perhaps a nasalised variant of chub (“someone chubby, something thick”). Compare Icelandic kubbur (“block of wood, chip (computing)”), Old Norse kumbr for kubbr (“block of wood”), English chop.

Etymology from Wiktionary, CC BY-SA 3.0