go under the knife
Meaning
To have surgery; to undergo an operation, especially a medical procedure involving cutting.
Origin
A figurative reference to a surgeon’s knife/scalpel. “Under the knife” has been used since the 19th century to mean being operated on; “go under” emphasizes undergoing the procedure (often with anesthesia).
Notes
Common, informal way to say “have surgery.” Can sound a bit graphic; in formal/medical contexts, “undergo surgery” is safer.
Examples
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After months of pain, she finally decided to go under the knife for a knee replacement.
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He went under the knife last week to remove his appendix, and he’s already back at work.
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The actor refused to go under the knife and chose physical therapy instead.
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If the infection doesn’t clear up soon, you may have to go under the knife.
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She was nervous about going under the knife, but the surgeon explained the procedure in detail.
Grammar & Usage Notes
Usually used as “go under the knife” or “have to go under the knife.” Tense can change (went/going). Often followed by “for + condition/body part” (e.g., for her knee).
Synonyms
- have surgery
- undergo surgery
- have an operation
- go in for surgery
Antonyms
- avoid surgery
- treat non-surgically