under the knife

Idioms  

1. Undergoing surgery, as in He was awake the entire time he was under the knife. The phrase is often put as go under the knife meaning “be operated on,” as in When do you go under the knife? Knife standing for “surgery” was first recorded in 1880.

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Example Sentences

See Examples For:

under the knife

But Standard Oil finally went under the knife in 1911, split into 34 separate companies that sometimes seem like they are bent on reunifying.

From Barron's ● May 2, 2026

The larger-than-life footballer died of heart failure and acute pulmonary edema -- a condition where fluid accumulates in the lungs -- two weeks after going under the knife.

From Barron's ● Apr. 23, 2026

Williams' cautiousness about going under the knife suggests he still has ambitions to continue on the baize for years to come - and who can blame him.

From BBC ● Apr. 17, 2026

Patients who went under the knife late last year are now debuting tighter skin, flatter stomachs and lifted eyelids to their social networks.

From The Wall Street Journal ● Feb. 7, 2026

He volunteered to be one of six people in the country to go under the knife for experimental brain surgery that would possibly provide him with a few more years of functionality.

From "Geeks: How Two Lost Boys Rode the Internet Out of Idaho" by Jon Katz