in situ

adverb or adjective

in si·​tu (ˌ)in-ˈsī-(ˌ)tü 

-ˈsi-,

-(ˌ)tyü 

 also  -ˈsē-,

-(ˌ)chü 

: in the natural or original position or place

an in situ cancer confined to the breast duct

Examples of in situ in a Sentence

Recent Examples on the Web

The test is intended as a next generation of diagnostics, enabling more accurate diagnosis than the current standard, fluorescence in situ hybridization, without requiring the painful intrusion of a bone marrow biopsy. —Alex Knapp, Forbes.com, 30 Apr. 2025

For now, the researchers have left the ship in situ, partially covering it with original soil and squeezing wet sponges onto it to preserve moisture. —Eli Wizevich, Smithsonian Magazine, 30 Apr. 2025

The best chance to find life beyond the Earth is through planetary exploration using in situ observations or sample return, says Kwok. —Bruce Dorminey, Forbes.com, 26 Apr. 2025

Photo: James Merrell How to test paint colors How color behaves in relation to other colors and in different light conditions is extremely complex, and nothing beats seeing them in situ, Studholme says. —Ariel Okin, Vogue, 18 Apr. 2025

Word History

Etymology

Latin, in position

First Known Use

1740, in the meaning defined above

Rhymes for in situ

• amadou
• avenue
• ballyhoo
• baraboo
• barbecue
• barbeque
• bugaboo
• cabildo
• caribou
• cockatoo
• detinue
• devalue

Kids Definition

in situ

adverb or adjective

in si·​tu (ˈ)in-ˈsī-t(y)ü 

-ˈsi-

: in the natural or original position

the cancer cells remained in situ

Etymology

Latin, "in position"

Medical Definition

in situ

adverb or adjective

in si·​tu

(ˈ)in-ˈsī-(ˌ)t(y)ü, -ˈsi- also -ˈsē-, -(ˌ)chü

: in the natural or original position or place

an in situ cancer confined to the breast duct

see carcinoma in situ