/in suy"tooh, -tyooh, see"-/ ; Latin. /in sit"ooh/
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. Med.
a. in place or position; undisturbed.
b. in a localized state or condition: carcinoma in situ.
[ 1730-40; in situ lit., in place ]