Around this time of year, we’re all loosening our belts and getting ready to gorge ourselves on hot, gravy-laden turkey. So we couldn’t help but wonder about things at the opposite end of the temperature spectrum: the “cold turkey” invoked when people up and quit some substance, behavior or habit suddenly. According to the OED, the phrase first appeared in print in the early 20th century, and was later tied specifically to quitting addictive substances in the 1920s, but its exact origin is unclear.
One possibility is that it evolved from the older idiom “talking turkey” (the origin of which is likewise elusive and might go back to the trading of fowl between Native Americans and European colonists, or this often-repeated story of a hunting trip), and sometimes appeared in the 19th and early 20th centuries as “talking cold turkey.” Since that phrase already meant “to speak frankly and plainly,” to quit something cold turkey might have naturally followed to mean abandoning something with similar directness.
Another possibility is that it stems from actual cold pieces of turkey. To make cold, leftover bits of the bird into a meal requires very little preparation, as does abruptly quitting something.
One final suggested origin is that the phrase comes from the similarities between a drug addict in the throes of withdrawal and a turkey’s carcass. Both can be clammy, pale and covered in goosebumps, which might have led someone to point out that a user who suddenly quit looked like a cold turkey.