in si·tu /ɪn ˈsaɪtu, -tyu, ˈsi-; Lat. ɪn ˈsɪtu/ Pronunciation Key - [in sahy-too, -tyoo, see-; Lat. in sit-oo]
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.
a. in place or position; undisturbed.
b. in a localized state or condition: carcinoma in situ.