In situ means something situated in its natural or original position. In situ may be used as an adjective or adverb, it is Latin and came into use in the middle of the eighteenth century. The literal translation of in situ is on site.
In situ is used in archaeology to refer to an artifact that has not been removed from the place where it was found. In art, in situ refers to a work of art that remains where it was installed. In biology, in situ means to study the phenomenon or object of interest in the exact locale it belongs in. In psychology, in situ denotes an experiment done in the field, rather than in the laboratory.
Altogether, the excavators say, they uncovered at least 120 restorable jars still in situ in four storage rooms in the southern storage area of the palace (including pieces found in the last seasons). (Haaretz)
A roughly-five-meter long fire pit which was recently discovered by an archaeological dig at Lækjargata in Reykjavík will be allowed to remain in situ, it has now been decided. (Iceland Review)
In the 1950s, Dr. Jones collaborated on landmark studies with Dr. Richard Wesley TeLinde, proving that cervical cancer in situ — in which tumors have not invaded the cervix’s surface — was more dangerous than previously thought. (The Boston Globe)
One work is a substantial three-by-six metres, consisting of 14 panels of painted aluminium mounted on rusted Corten steel that had to be welded together in situ. (The Financial Times)
Office environments are neither more rigorous nor more intellectually demanding than those of schools and there is nothing a young architect would not learn expeditiously in situ in the office and on the fly. (Architects Newspaper)