in situ

American  

[in sahy-too, -tyoo, see-, in sit-oo] / ɪn ˈsaɪ tu, -tju, 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

See Examples For:

in situ

More recently, I tidied the home of a friend who was in the hospital, the pill bottles and crumpled blankets left in situ as evidence of someone else’s pain.

From Los Angeles Times ● May 28, 2026

Kearns continued: "The child was completely dry. They had a nappy in situ, which appeared to be appropriately placed."

From BBC ● May 5, 2026

They also demonstrate the power of in situ microscopic imaging at the single-particle level for uncovering reaction pathways in catalytic systems.

From Science Daily ● Apr. 21, 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

I had the great luck one summer of studying the three-toed sloth in situ in the equatorial jungles of Brazil.

From "Life of Pi" by Yann Martel

Related Words

• situated