large sea fish, edible and widely distributed in colder seas, 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 cod-piece). Codfish is from 1560s. Cod-liver oil, known at least since 1610s, was recommended medicinally from 1783 but did not become popular as a remedy until after 1825.
type of cephalopod, 1590s, earlier simply cuttle, from Old English cudele "the cuttlefish;" first element perhaps related to Middle Low German küdel "container, pocket;" Old Norse koddi "cushion, testicle;" and Old English codd (see cod). In 17c. sometimes scuttlefish.
also codpiece, mid-15c., in male costume c. 1450-1550, a bagged appendage to the front of close-fitting breeches, "often conspicuous and ornamented" [OED], from Old English codd "a bag, pouch, husk," in Middle English, "testicles" (cognate with Old Norse koddi "pillow; scrotum") + piece (n.1).
said to be from 19c. (but first attested 1959), perhaps from wallop, British slang for "beer," and cod in one of its various senses, perhaps "testicles" (a 1966 citation in OED spells it cod's wallop).
cod-like sea fish, early 15c., poullok, apparently a transferred use of a Celtic name of a similar-looking freshwater fish (compare Gaelic pollag, Irish pollóg).
"purse-like tegumentary investment of the testes and part of the spermatic cord; the cod" [Century Dictionary], 1590s, from Latin scrotum, which probably is transposed from scortum "a skin, hide" (see corium), perhaps by influence of scrautum "leather quiver for arrows." Related: Scrotal.
"elongated seed vessel of beans, peas, etc.," 1680s, a word of uncertain origin; found earlier in podware "seed of legumes, seed grain" (mid-15c.), which had a parallel form codware "husked or seeded plants" (late 14c.), related to cod "husk of seeded plants," which was in Old English. In reference to a round belly from 1825; in reference to pregnancy from 1890. Meaning "detachable body of an aircraft" is from 1950.
Pod people (1956) was popularized by the movie "Invasion of the Body Snatchers," based on the 1954 novel by U.S. author Jack Finney about a plant-like alien life form that arrives on Earth as pods and are capable of replicating people.