in situ

American  

[in sahy-too, -tyoo, see-, in sit-oo] / ɪn ˈsaɪ tu, -tyu, ˈsi-, ɪn ˈsɪt u /

adverb

1. situated in the original, natural, or existing place or position.

   The archaeologists were able to date the vase because it was found in situ.

2. Medicine/Medical.

   1. in place or position; undisturbed.

   2. (especially of a malignant tumor) in a localized state or condition.

      carcinoma in situ.

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in situ British  

/ ɪn ˈsɪtjuː /

adverb

1. in the natural, original, or appropriate position

2. pathol (esp of a cancerous growth or tumour) not seen to be spreading from a localized position

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in situ Cultural  

1. In the original place or arrangement: “The body was left in situ until the police arrived.” From Latin, meaning “in position.”

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Etymology

Origin of in situ

First recorded in 1730–40, in situ is from Latin in sitū literally, “in place”

Example Sentences

He said X-ray examinations had failed to give a clear picture of one of the fuses, which meant it had to be blown in situ.

From BBC • May 1, 2026

A painstaking three days were spent examining the skeleton in situ before he was removed, with all but a small toe bone recovered.

From BBC • Apr. 27, 2026

As for the Mother Tree Project, it found that the more towering beauties left in situ, the better for all types of seedlings and plants in the test sites.

From The Wall Street Journal • Apr. 17, 2026

There are other conditions highlighted that need to be in situ at this point for a stock market rally to develop.

From MarketWatch • Mar. 6, 2026

In this particular study—the largest ever done on the relationship between the two cervical cancers—Jones and TeLinde found that 62 percent of women with invasive cancer who’d had earlier biopsies first had carcinoma in situ.

From "The Immortal Life of Henrietta Lacks" by Rebecca Skloot

Related Words

• situated