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

Participants will spend time practicing functional repairs in situ, and laying out replacement timbers using 'old school mill rule' techniques thought to have been used during the original construction of the barn. —Deb Harvell, arkansasonline.com, 27 Oct. 2024

Laser-assisted in situ keratomileusis, commonly known as LASIK, is the most common type of laser eye surgery. —Vanessa Caceres, Verywell Health, 11 Sep. 2024

Many roads have been bombed, too, trapping people in situ. —Rania Abouzeid, The New Yorker, 11 Oct. 2024

The amazing app is demonstrated in the video below, showing it being used in situ in a user’s home: The video is a staggering demonstration of the Vision Pro’s 3D processing power. —Barry Collins, Forbes, 2 Oct. 2024

Word History

Etymology

Latin, in position

First Known Use

1740, in the meaning defined above

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