The sudden and complete withdrawal from an addictive substance and/or the physiological effects of such a withdrawal. Also, predominantly in the U.S.A., plain speaking.
At this time of year you have probably had enough of cold turkey to last until next year's festivities. Nevertheless, here's another plateful.
The term 'cold turkey' is now predominantly used as the name of the drug withdrawal process. Also, by extension, it is used to refer to any abrupt termination of something we are accustomed to. To find the origin of the term we need to delve into the annals of American speech. Let's talk turkey.
The turkey looms large in the American psyche because of its link to early European colonists and is, as even Limies like me know, the centrepiece of the annual Thanksgiving meal. In the USA, and as far as I can tell nowhere else, 'plain speaking/getting down to business' is called 'talking cold turkey'. This usage dates from the early part of the 20th century, as in this example from The Des Moines Daily News, May 1914:
I've heard [Reverend Billy] Sunday give his 'Booze' sermon, and believe me that rascal can make tears flow out of a stone. And furthermore he talks "cold turkey". You know what I mean - calls a spade a spade.
The English newspaper The Daily Express introduced the phrase to an English audience in a January 1928 edition:
"She talked cold turkey about sex. 'Cold turkey' means plain truth in America."
'Talking cold turkey' meant no nonsense talking and its partner expression 'going cold turkey' meant no nonsense doing. To 'go cold turkey' was to get straight to the scene of the action - in at the deep end. An example of it in use is found in Debates: the official reports of the Canadian House of Commons, 1899:
I am told that other countries, for instance Australia, have gone cold turkey all the way. They have gone full metric and have experienced less difficulty in the implementation of their program over the long-term.
The earliest reference to 'cold turkey' in relation to drug withdrawal that I can find is from the Canadian newspaper The Daily Colonist, October 1921:
"Perhaps the most pitiful figures who have appeared before Dr. Carleton Simon are those who voluntarily surrender themselves. When they go before him, they [drug addicts] are given what is called the 'cold turkey' treatment."
In the state of drug withdrawal the addict's blood is directed to the internal organs, leaving the skin white and with goose bumps. It has been suggested that this is what is alluded to by 'cold turkey'. There's no evidence to support that view. For the source of 'cold turkey' we need look no further than the direct, no nonsense approach indicated by the earlier 'in at the deep end' meaning of the term.
See
other phrases that were coined in the USA.