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

Sandy Springs resident Stacey Hughes, 53, has participated in the race nearly every year since being diagnosed with stage 0 ductal carcinoma in situ in 2017. — Nicole Bennett, AJC.com, 16 Oct. 2026

Experts are starting to question whether identifying ductal carcinoma in situ as cancer leads to unnecessary interventions such as radiation and surgery. — Mikkael A. Sekeres, Washington Post, 12 Oct. 2026

But while all objects exist in time, any artwork that is site-specific exists in situ. — Jeffrey Weiss, Artforum, 1 Oct. 2026

This easy trail has interpretive signs pointing out Jurassic-age plant and animal fossils in situ. — Kristen Kidd, Denver Post, 22 Sep. 2026

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