codyoudaoicibaDictYouDict[cod 词源字典]
cod: [13] Like most fish-names, the origins of cod are obscure. It has been suggested, not all that convincingly, that it comes from another word cod [OE], now obsolete, which meant broadly ‘pouch’ – the idea being that the fish supposedly has a ‘baglike’ appearance. Among the specific applications of this other cod, which was of Germanic origin, were ‘seedcase’ (which survived into the twentieth century in the archaic compound peascod ‘pea pod’) and ‘scrotum’.

By transference the latter came to mean ‘testicles’, whence codpiece, a 15th- to 17thcentury garment somewhat analogous to the jockstrap. The cuttle of cuttlefish comes from the same source.
=> cuttlefish[cod etymology, cod origin, 英语词源]
cod (n.)youdaoicibaDictYouDict
large sea fish, mid-14c. (late 13c. in a surname, Thomas cotfich), of unknown origin; despite similarity of form it has no conclusive connection to the widespread Germanic word for "bag" (represented by Old English codd, preserved in codpiece). Cod-liver oil known since at least 1610s, was recommended medicinally since 1783, but not popular as a remedy until after 1825.