/ Dictionary / Index I in situ: Meaning and Definition of Find definitions for: in si•tu Pronunciation: (in sī't, -ty, sē'-Latin.in sit'), [key] situated in the original, natural, or existing place or position: The archaeologists were able to date the vase because it was found in situ. carcinoma in situ. in place or position; undisturbed. in a localized state or condition:carcinoma in situ. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. insistent insnare Related Content Daily Word Quiz: sequester Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language