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

This study presents boron isotopes as in situ tracers for studying glass dissolution mechanisms, assisting in predicting contaminant releases during waste glass-aqueous solution interactions. —Prabhat Ranjan Mishra, Interesting Engineering, 16 Oct. 2025

On an August 2024 episode of Pod Meets World, the actress revealed she had been diagnosed with an early form of breast cancer called ductal carcinoma in situ (DCIS). —Kate Hogan, PEOPLE, 14 Oct. 2025

Current head coach Jose Luis Mendilibar has been in situ since February last year, and delivered a UEFA Conference League final triumph. —Paul Taylor, New York Times, 8 Oct. 2025

The designer and her team will be in situ to welcome customers and take measurements. —Alex Wynne, Footwear News, 3 Oct. 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