cold turkey

Sl. immediately; without tapering off or cutting down gradually. (Originally drug slang. Now used of breaking any habit.) Tom stopped smoking cold turkey. She gave up her drinking habit cold turkey and had no ill effects.

the unpleasant physical and mental effects someone suffers when they suddenly stop taking drugs The addict himself must make the decision that he wants to go cold turkey. The nurses are there to encourage patients through cold turkey.

Immediate, complete withdrawal from something, especially an addictive substance; also, without planning or preparation. For example, My bad shoulder forced me to quit playing tennis cold turkey, or I'd never done any rock climbing, but decided to try it cold turkey. This term may have come from the earlier expression talk turkey (for blunt speaking). At first used strictly for abrupt withdrawal from drugs or alcohol, it soon was transferred to quitting any habit or activity. [Early 1900s]