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

The Morning Star Missions to Venus initiative is developing in situ techniques for studying the chemistry of Venus's clouds.

From Science Daily ● Sep. 13, 2026

The obelisk was displaced to Paris, certainly, and the Rosetta Stone, also hitherto neglected in situ, went to Britain.

From The Wall Street Journal ● Sep. 12, 2026

To many, it seemed new businesses were popping up that had little obvious purpose or, in many cases, a huge number of direct competitors already in situ.

From BBC ● Jun. 7, 2026

According to the researchers, fire whirls can burn crude oil nearly twice as fast as traditional in situ fire pools.

From Science Daily ● Jun. 5, 2026

In 1951, most doctors in the field believed that invasive carcinoma was deadly, and carcinoma in situ wasn’t.

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

Related Words

• situated